377 results
Search Results
2. Oxytocic polypeptides in human urine.
- Author
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WALASZEK EJ
- Subjects
- Animals, Female, Rats, Bradykinin, Dental Pulp, Furans, Muscles physiology, Oxytocics, Paper, Peptides, Serum Globulins, Work
- Abstract
The work of Gomes on the polypeptide in human urine which causes contraction of the rat uterus has been extended. Concentrates were prepared by means of paper pulp columns similar to those used by Rocha e Silva and his colleagues for the purification of bradykinin, and evidence was obtained for the presence of two different active substances not only in human urine but also in a preparation of bradykinin. The effect of human urine on the rat uterus is probably due to bradykinin itself or a mixture of similar substances.
- Published
- 1957
- Full Text
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3. Kininogenase of the guinea-pig's coagulating gland and the release of bradykinin.
- Author
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Moriwaki C and Schachte M
- Subjects
- Animals, Arginine, Chromatography, Chromatography, Gel, Chromatography, Paper, Chromatography, Thin Layer, Esters, Guinea Pigs, Male, Methylcellulose, Protease Inhibitors, Serum Globulins, Tosyl Compounds, Bradykinin, Endopeptidases isolation & purification, Genitalia, Male enzymology
- Abstract
A kininogenase (CGK) in the coagulating gland of the guinea-pig was partially purified, characterized and separated from a kininase also present in the gland. This kininogenase is not inhibited by the usual kininogenase and protease inhibitors. Our results indicate that it is identical with the esterolytic enzyme in the gland which hydrolyses the synthetic ester TAME. The kinin released by CGK from dog's crude pseudoglobulin was purified more than 1500 times and identified as bradykinin by chromatography on paper, on carboxymethyl-cellulose columns, and on silica gel.
- Published
- 1971
- Full Text
- View/download PDF
4. Radiommunoassay of bradykinin.
- Author
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Rinderknecht H, Haverback BJ, and Aladjem F
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- Animals, Antibody Formation, Carbon metabolism, Carbon Isotopes, Chromatography, Paper, Goats, Hemocyanins, Immune Sera, Immunization, Protein Binding, Tritium, Bradykinin analysis, Immunoassay
- Published
- 1967
- Full Text
- View/download PDF
5. All-D-bradykinin and the problem of peptide antimetabolites.
- Author
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Stewart JM and Woolley DW
- Subjects
- Animals, Biological Assay, Chemical Phenomena, Chemistry, Chemistry Techniques, Analytical, Chromatography, Paper, Countercurrent Distribution, Duodenum drug effects, Electrophoresis, Female, In Vitro Techniques, Muscle, Smooth drug effects, Rats, Stomach drug effects, Uterus drug effects, Antimetabolites, Bradykinin
- Published
- 1965
- Full Text
- View/download PDF
6. Formation of bradykinin from kallidin-10 by aminopeptidase B.
- Author
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Hopsu-Havu VK, Mäkinen KK, and Glenner GG
- Subjects
- Chromatography, Paper, Aminopeptidases metabolism, Bradykinin biosynthesis, Kallidin metabolism
- Published
- 1966
- Full Text
- View/download PDF
7. Evidence for the release of bradykinin in carcinoid syndrome.
- Author
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Oates JA, Pettinger WA, and Doctor RB
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- Animals, Chromatography, Paper, Electrophoresis, Female, Humans, Rats, Uterus drug effects, Bradykinin metabolism, Bradykinin pharmacology, Malignant Carcinoid Syndrome metabolism
- Published
- 1966
- Full Text
- View/download PDF
8. Understanding COVID-19 outcome: Exploring the prognostic value of soluble biomarkers indicative of endothelial impairment.
- Author
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Mariappan V, Adla D, Jangili S, Ranganadin P, Green SR, Mohammed S, Mutheneni SR, and Pillai AB
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- Humans, Female, Male, Middle Aged, Prognosis, Adult, Aged, Fibrin Fibrinogen Degradation Products metabolism, Fibrin Fibrinogen Degradation Products analysis, Severity of Illness Index, Endothelium, Vascular metabolism, Kallikreins blood, alpha 1-Antitrypsin blood, COVID-19 blood, COVID-19 diagnosis, Biomarkers blood, Interleukin-18 blood, SARS-CoV-2, Bradykinin blood
- Abstract
Host proteins released by the activated endothelial cells during SARS-CoV-2 infection are implicated to be involved in coagulation and endothelial dysfunction. However, the underlying mechanism that governs the vascular dysfunction and disease severity in COVID-19 remains obscure. The study evaluated the serum levels of Bradykinin, Kallikrein, SERPIN A, and IL-18 in COVID-19 (N-42 with 20 moderate and 22 severe) patients compared to healthy controls (HC: N-10) using ELISA at the day of admission (DOA) and day 7 post-admission. The efficacy of the protein levels in predicting disease severity was further determined using machine learning models. The levels of bradykinins and SERPIN A were higher (P ≤ 0.001) in both severe and moderate cases on day 7 post-admission compared to DOA. All the soluble proteins studied were found to elevated (P ≤ 0.01) in severe compared to moderate in day 7 and were positively correlated (P ≤ 0.001) with D-dimer, a marker for coagulation. ROC analysis identified that SERPIN A, IL-18, and bradykinin could predict the clinical condition of COVID-19 with AUC values of 1, 0.979, and 1, respectively. Among the models trained using univariate model analysis, SERPIN A emerged as a strong prognostic biomarker for COVID-19 disease severity. The serum levels of SERPIN A in conjunction with the coagulation marker D-dimer, serve as a predictive indicator for COVID-19 clinical outcomes. However, studies are required to ascertain the role of these markers in disease virulence., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)
- Published
- 2024
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9. Mast cell degranulation and bradykinin-induced angioedema - searching for the missing link.
- Author
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Porebski G, Dziadowiec A, Rybka H, Kitel R, and Kwitniewski M
- Subjects
- Humans, Animals, Angioedema metabolism, Angioedema immunology, Angioedema etiology, Nerve Tissue Proteins metabolism, Kallikrein-Kinin System physiology, Mast Cells immunology, Mast Cells metabolism, Cell Degranulation, Bradykinin metabolism, Receptors, G-Protein-Coupled metabolism, Receptors, Neuropeptide metabolism
- Abstract
Initiation of the bradykinin generation cascade is responsible for the occurrence of attacks in some types of angioedema without wheals. Hereditary angioedema due to C1 inhibitor deficiency (HAE-C1-INH) is one such clinical entity. In this paper, we explore the existing evidence that mast cells (MCs) degranulation may contribute to the activation of the kallikrein-kinin system cascade, followed by bradykinin formation and angioedema. We present the multidirectional effects of MC-derived heparin and other polyanions on the major components of the kinin-kallikrein system, particularly on the factor XII activation. Although, bradykinin- and histamine-mediated symptoms are distinct clinical phenomena, they share some common features, such as some similar triggers and a predilection to occur at sites where mast cells reside, namely the skin and mucous membranes. In addition, recent observations indicate a high incidence of hypersensitivity reactions associated with MC degranulation in the HAE-C1-INH patient population. However, not all of these can be explained by IgE-dependent mechanisms. Mast cell-related G protein-coupled receptor-X2 (MRGPRX2), which has recently attracted scientific interest, may be involved in the activation of MCs through a different pathway. Therefore, we reviewed MRGPRX2 ligands that HAE-C1-INH patients may be exposed to in their daily lives and that may affect MCs degranulation. We also discussed the known inter- and intra-individual variability in the course of HAE-C1-INH in relation to factors responsible for possible variability in the strength of the response to MRGPRX2 receptor stimulation. The above issues raise several questions for future research. It is not known to what extent a prophylactic or therapeutic intervention targeting the pathways of one mechanism (mast cell degranulation) may affect the other (bradykinin production), or whether the number of mast cells at a specific body site and their reactivity to triggers such as pressure, allergens or MRGPRX2 agonists may influence the occurrence of HAE-C1-INH attacks at that site., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The handling editor MR declared a past co-authorship with the author GP., (Copyright © 2024 Porebski, Dziadowiec, Rybka, Kitel and Kwitniewski.)
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- 2024
- Full Text
- View/download PDF
10. Bradykinin regulates cell growth and migration in cultured human cardiac c-Kit+ progenitor cells
- Author
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Gui-Rong Li, Gang Li, and Yan Wang
- Subjects
0301 basic medicine ,MAPK/ERK pathway ,medicine.medical_specialty ,Receptor, Bradykinin B2 ,proliferation ,Blotting, Western ,Bradykinin ,Gene Expression ,bradykinin receptor 2 ,migration ,Receptor, Bradykinin B1 ,03 medical and health sciences ,chemistry.chemical_compound ,Phosphatidylinositol 3-Kinases ,Cyclin D1 ,Cell Movement ,Internal medicine ,Pathology Section ,medicine ,Humans ,Heart Atria ,Progenitor cell ,Bradykinin receptor ,Receptor ,Extracellular Signal-Regulated MAP Kinases ,PI3K/AKT/mTOR pathway ,Cells, Cultured ,Protein Kinase C ,Cell Proliferation ,human cardiac c-Kit+ ,Dose-Response Relationship, Drug ,Cell growth ,Reverse Transcriptase Polymerase Chain Reaction ,Stem Cells ,Cell Cycle ,progenitor cells ,Molecular biology ,Research Paper: Pathology ,Proto-Oncogene Proteins c-kit ,030104 developmental biology ,Endocrinology ,Oncology ,chemistry ,Type C Phospholipases ,RNA Interference ,Proto-Oncogene Proteins c-akt - Abstract
// Gang Li 1,2 , Yan Wang 1 and Gui-Rong Li 1,2 1 Xiamen Cardiovascular Hospital, Xiamen University, Xiamen, Fujian, China 2 Department of Medicine, Li Ka Shing Faculty of Medicine, University of Hong Kong, Pokfulam, Hong Kong, China Correspondence to: Yan Wang, email: // Gui-Rong Li, email: // Keywords : Bradykinin; bradykinin receptor 2; human cardiac c-Kit+ progenitor cells; proliferation; migration; Pathology Section Received : June 27, 2016 Accepted : January 06, 2017 Published : January 12, 2017 Abstract Bradykinin is a well-known endogenous vasoactive peptide. The present study investigated the bradykinin receptor expression in human cardiac c-Kit + progenitor cells and the potential role of bradykinin in regulating cell cycling progression and mobility. It was found that mRNA and protein of bradykinin type 2 receptors, but not bradykinin type 1 receptors, were abundant in cultured human cardiac c-Kit + progenitor cells. Bradykinin (1-10 nM) stimulated cell growth and migration in a concentration-dependent manner. The increase of cell proliferation was related to promoting G0/G1 transition into G2/M and S phase. Western blots revealed that bradykinin significantly increased pAkt and pERK1/2 as well as cyclin D1, which were countered by HOE140 (an antagonist of bradykinin type 2 receptors) or by silencing bradykinin type 2 receptors. The increase of pAkt, pERK1/2 and cyclin D1 by bradykinin was prevented by the PI3K inhibitor Ly294002, the PLC inhibitors U73122 and neomycin, and/or the PKC inhibitor chelerythrine and the MAPK inhibitor PD98059. Our results demonstrate the novel information that bradykinin promotes cell cycling progression and migration in human cardiac c-Kit + progenitor cells via activating PI3K, PLC, PKC, cyclin D1, pERK1/2, and pAkt.
- Published
- 2017
11. Blockade of the kallikrein-kinin system reduces endothelial complement activation in vascular inflammation
- Author
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Davalieva, Katarina, Makridakis, Manousos, Vlahou, Antonia, Frantzi, Maria, Boizard, Franck, Moussaoui, Nabila, Lescat, Ophélie, Fedou, Camille, Feuillet, Guylène, Casemayou, Audrey, Neau, Eric, Decatte, Luc, Raaijmakers, Anke, Vayssière, Christophe, Goua, Valérie, Lucas, Charlotte, Benachi, Alexandra, Delmas, Hélène Laurichesse, Allain-Launay, Emma, Boudailliez, Bernard, Simon, Elisabeth, Noel, Catherine, Floch, Corinne, Bourdat-Michel, Guylène, Weingertner, Anne-Sophie, Oury, Jean-François, Baudouin, Véronique, Bory, Jean-Paul, Pietrement, Christine, Fiorenza, Maryse, Kessler, Sylvie, Auriol, Françoise Conte, Marcorelles, Pascale, Collardeau-Frachon, Sophie, Magalhães, Pedro, Batut, Julie, Blader, Patrick, Saulnier Blache, Jean-Sebastien, Allegaert, Karel, Aubard, Yves, Basmaison, Odile, Benevent, Jean-Baptiste, Biquard, Florence, Champion, Gérard, Delbosc, Jean-Marie, Eckart, Philippe, Gaucherand, Pascal, Guigonis, Vincent, Hougas, Blandine, Martin, Alain, Martin, Sophie, Maupin-Hyvonnet, Mariannick, Merveille, Marina, Mousty, Eve, Nobili, François, Taque, Sophie, Latosinska, Agnieszka, Faguer, Stanislas, Beige, Joachim, van der Zanden, Loes, Levtchenko, Elena, Moulos, Panogiotis, Lounis, Nadia, Conte-Auriol, Françoise, Olsen, Henning, Hindryckx, An, De Catte, Luc, Vayssieres, Christophe, Sartor, Agnes, Groussolles, Marion, Plard, Christelle, Guerby, Paul, Connan, Laure, Morin, Mathieu, Simon, Elizabeth, Breaud, Jean, Saliou, Anne-Hélène, De Parscau, Loic, Jay, Nadine, Germouty, Isabelle, Le Bouar, Gwenaelle, Ryckewaert, Amelie, Manca-Pellissier, Marie-Christine, Merrot, Thierry, Laurichesse, Helene, Gallot, Denis, Bessenay, Lucie, Bidat, Laurent, Boize, Philippe, Winer, Norbert, Allain-Launey, Emma, Le Vaillant, Claudine, Prieur, Fabienne, Lavocat, Marie-Pierre, Coatleven, Frederic, Debromez, Eric, Harembat, Jérôme, Llanas, Brigitte, Favre, Romain, Moog, Raphael, Zaloszyc, Ariane, Massardier, Jérôme, DEMEDE, Delphine, Perrotin, Franck, Cloarec, Sylvie, Vequeau-Goua, Valérie, Descombes, Emmanuelle, Boulot, Pierre, Morin, Denis, Fuchs, Florent, Tenenbaum, Julie, Ville, Yves, Blanc, Thomas, Heidet, Laurence, Paris, Anne, Dobremez, Eric, Froute, Marie-Françoise, Gondry, Jean, Muszynski, Charles, Haraux, Elodie, Lobelle, Fabienne, Chevreau, Julien, Rosenblatt, Jonathan, Baudoin, Véronique, Deschenes, Georges, Guigue, Virginie, Amblard, Florence, Bourdat-Michel, Guylhène, Wühl, Elke, Schaefer, Franz, Elsässer, Michael, Persico, Nicola, Rossi, Federica, Manzoni, Gianantonio, De Marco, Erika, Montini, Giovanni, Capone, Valentina, Caforio, Leonardo, Zaccara, Antonio, Innocenzi, Michele, Bagolan, Pietro, Capozza, Nicola, Castagnetti, Marco, Mancini, Mariangela, Oepkes, Dick, van Scheltema, Phebe Adama, Feitz, Wout, Kortmann, Barbara, Schreuder, Michiel, Pawłowska, Barbara, Fortecka-Piestrzeniewicz, Katarzyna, Olejniczak, Dariusz, Ariceta, Gema, Arevalo, Silvia, RODO, Carlota, Fossum, Magdalena, Lindgren, Peter, Parvex, Paloma, Chehade, Hassib, He, Tianlin, Metzger, Jochen, Mullen, William, Mischak, Harald, Zürbig, Petra, Jankowski, Vera, Buffin-Meyer, Bénédicte, Tkaczyk, Marcin, Stańczyk, Małgorzata, Breuil, Benjamin, Siwy, Justyna, Szaflik, Krzysztof, Talar, Tomasz, Wojtera, Justyna, Krzeszowski, Waldemar, Decramer, Stéphane, Lopatko Fagerström, Ingrid, Ståhl, Anne-lie, Mossberg, Maria, Tati, Ramesh, Kristoffersson, Ann-Charlotte, Kahn, Robin, Bascands, Jean-Loup, Klein, Julie, Schanstra, Joost, Segelmark, Mårten, Karpman, Diana, Department of Pediatrics [Lund, Sweden] (Clinical Sciences), Lund University [Lund], Wallenberg Center for Molecular Medicine [Lund, Sweden], Diabète athérothrombose et thérapies Réunion Océan Indien (DéTROI), Université de La Réunion (UR)-Institut National de la Santé et de la Recherche Médicale (INSERM), Institut des Maladies Métaboliques et Cardiovasculaires (I2MC), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National de la Santé et de la Recherche Médicale (INSERM), Department of Nephrology [Lund, Sweden] (Clinical Sciences Lund), Department of Medical and Health Sciences [Lund, Sweden], Linköping University (LIU), The study was supported by The Swedish Research Council (K2015-99X-22877-01-6 and 2017-01920), The Knut and Alice Wallenberg Foundation (Wallenberg Clinical Scholar 2015.0320), The Torsten Söderberg Foundation, Skåne Centre of Excellence in Health, IngaBritt och Arne Lundberg's Research Foundation, Crown Princess Lovisa's Society for Child Care, Region Skåne and The Konung Gustaf V:s 80-årsfond (all to DK). Alfred Österlund Foundation (to LMFLL and RK). TheWallenberg Center forMolecular Medicine, The Swedish RheumatismAssociation, The Anna-Greta Crafoord Foundation, Greta and Johan Kock's Foundation, the Samariten Foundation, Fanny Ekdahl foundation, the Jerring foundation and the Thelma Zoegas Foundation (to RK). JPS and JK were partially funded by a grant from the 'Fondation pour la Recherche Médicale' (grant number DEQ20170336759). MS was funded by The Swedish Rheumatism Association and the Ingrid Asp Foundation., Schanstra, Joost, Macedonian Academy of Sciences and Arts [Skopje, North Macedonia] (MASA), Biomedical Research Foundation of the Academy of Athens (BRFAA), Mosaiques Diagnostics & Therapeutics (MOSAIQUES DIAGNOSTICS & THERAPEUTICS), Mosaiques Diagnostics & Therapeutics AG, Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées, Institut de médecine moléculaire de Rangueil (I2MR), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-IFR150-Institut National de la Santé et de la Recherche Médicale (INSERM), CHU Toulouse [Toulouse], KfH-Nierenzentrum und Klinikum St. Georg, Nephrologie, Leipzig, Radboud University Medical Center [Nijmegen], Catholic University of Leuven - Katholieke Universiteit Leuven (KU Leuven), HybridStat Predictive Analytics [Athens, Greece], Centre d'investigation clinique de Toulouse (CIC 1436), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-CHU Toulouse [Toulouse]-Institut National de la Santé et de la Recherche Médicale (INSERM), University Hospitals Leuven [Leuven], Heidelberg University Hospital [Heidelberg], University of Milan, Mosaiques Diagnostics GmbH [Hanovre, Allemagne], Institute of Cardiovascular and Medical Sciences [Glasgow], University of Glasgow, Universitätsklinikum RWTH Aachen - University Hospital Aachen [Aachen, Germany] (UKA), RWTH Aachen University, Polish Mother’s Memorial Hospital Research Institute [Lodz] (ICZMP), Mosaiques Diagnostics GmbH [Hannover, Germany], Mosaiques Diagnostics and Therapeutics AG [Hannover, Germany], Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de La Réunion (UR), and Université Fédérale Toulouse Midi-Pyrénées
- Subjects
0301 basic medicine ,Male ,Research paper ,Mouse ,Kallikrein-Kinin System ,[SDV]Life Sciences [q-bio] ,Pharmacology ,Kidney ,Mice ,0302 clinical medicine ,Glomerular C3 deposition ,Cell-Derived Microparticles ,Complement Activation ,Cells, Cultured ,Chemistry ,General Medicine ,Kinin ,Middle Aged ,Receptor antagonist ,3. Good health ,[SDV] Life Sciences [q-bio] ,medicine.anatomical_structure ,030220 oncology & carcinogenesis ,Female ,medicine.symptom ,Endothelial microvesicles ,Complement C1 Inhibitor Protein ,Protein Binding ,Vasculitis ,Complement ,Radiology, Nuclear Medicine and Medical Imaging ,Adult ,Endothelium ,medicine.drug_class ,Inflammation ,Bradykinin ,General Biochemistry, Genetics and Molecular Biology ,03 medical and health sciences ,Classical complement pathway ,medicine ,Animals ,Humans ,Aged ,Endothelial Cells ,Biological Transport ,Complement System Proteins ,Microvesicles ,Complement system ,Disease Models, Animal ,030104 developmental biology ,Immunoglobulin G ,Endothelium, Vascular ,Radiologi och bildbehandling - Abstract
Background: The complement and kallikrein-kinin systems (KKS) are activated during vascular inflammation. The aim of this study was to investigate if blockade of the KKS can affect complement activation on the endothelium during inflammation. Methods: Complement deposition on endothelial microvesicles was assayed in vasculitis patient plasma samples and controls. Plasma was perfused over glomerular endothelial cells and complement deposition assayed by flow cytometry. The effect of the kinin system was assessed using kinin receptor antagonists and C1-inhibitor. The in vivo effect was assessed in kidney sections from mice with nephrotoxic serum-induced glomerulonephritis treated with a kinin receptor antagonist. Findings: Vasculitis patient plasma had significantly more C3- and C9-positive endothelial microvesicles than controls. Perfusion of patient acute-phase plasma samples over glomerular endothelial cells induced the release of significantly more complement-positive microvesicles, in comparison to remission or control plasma. Complement activation on endothelial microvesicles was reduced by kinin B1- and B2-receptor antagonists or by C1-inhibitor (the main inhibitor of the classical pathway and the KKS). Likewise, perfusion of glomerular endothelial cells with C1-inhibitor-depleted plasma induced the release of complement-positive microvesicles, which was significantly reduced by kinin-receptor antagonists or C1-inhibitor. Mice with nephrotoxic serum-induced glomerulonephritis exhibited significantly reduced glomerular C3 deposition when treated with a B1-receptor antagonist. Interpretation: Excessive complement deposition on the endothelium will promote endothelial injury and the release of endothelial microvesicles. This study demonstrates that blockade of the KKS can reduce complement activation and thereby the inflammatory response on the endothelium. (C) 2019 The Authors. Published by Elsevier B.V. Funding Agencies|Swedish Research CouncilSwedish Research Council [K2015-99X-22877-01-6, 2017-01920]; Knut and Alice Wallenberg FoundationKnut & Alice Wallenberg Foundation [2015.0320]; Torsten Soderberg Foundation; Skane Centre of Excellence in Health; Crown Princess Lovisas Society for Child Care; Konung Gustaf V:s 80-arsfond; Alfred Osterlund Foundation; Wallenberg Center for Molecular Medicine; Swedish Rheumatism Association; Anna-Greta Crafoord Foundation; Greta and Johan Kocks Foundation; Samariten Foundation; Fanny Ekdahl foundation; Jerring foundation; Fondation pour la Recherche MedicaleFondation pour la Recherche Medicale [DEQ20170336759]; Ingrid Asp Foundation; IngaBritt och Arne Lundbergs Research Foundation; Region Skane; Thelma Zoegas Foundation
- Published
- 2019
12. The role of bradykinin receptor type 2 in spontaneous extravasation in mice skin: implications for non‐allergic angio‐oedema
- Author
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Bisha, Marion, Dao, Vu Thao‐Vi, Gholamreza‐Fahimi, Ehsan, Vogt, Michael, van Zandvoort, Marc, Weber, Sarah, Bas, Murat, Khosravani, Farbod, Kojda, Georg, and Suvorava, Tatsiana
- Subjects
Male ,Mice, Inbred C57BL ,Kinetics ,Mice ,Receptor, Bradykinin B2 ,Animals ,Edema ,Mice, Transgenic ,Bradykinin ,Research Papers ,Skin - Abstract
BACKGROUND AND PURPOSE: Non‐allergic angio‐oedema is a life‐threatening disease mediated by activation of bradykinin type 2 receptors (B(2) receptors). The aim of this study was to investigate whether activation of B(2) receptors by endogenous bradykinin contributes to physiological extravasation. This may shed new light on the assumption that treatment with an angiotensin converting enzyme inhibitor (ACEi) results in an alteration in the vascular barrier function predisposing to non‐allergic angio‐oedema. EXPERIMENTAL APPROACH: We generated a new transgenic mouse model characterized by endothelium‐specific overexpression of the B(2) receptor (B2(tg)) and established a non‐invasive two‐photon laser microscopy approach to measure the kinetics of spontaneous extravasation in vivo. The B2(tg) mice showed normal morphology and litter size as compared with their transgene‐negative littermates (B2(n)). KEY RESULTS: Overexpression of B(2) receptors was functional in conductance vessels and resistance vessels as evidenced by B(2) receptor‐mediated aortic dilation to bradykinin in presence of non‐specific COX inhibitor diclofenac and by significant hypotension in B2(tg) respectively. Measurement of dermal extravasation by Miles assay showed that bradykinin induced extravasation was significantly increased in B2(tg) as compared with B2(n). However, neither endothelial overexpression of B(2) receptors nor treatment with the ACEi moexipril or B(2) antagonist icatibant had any effect on spontaneous extravasation measured by two‐photon laser microscopy. CONCLUSIONS AND IMPLICATIONS: Activation of B(2) receptors does not appear to be involved in spontaneous extravasation. Therefore, the assumption that treatment with an ACEi results in an alteration in the physiological vascular barrier function predisposing to non‐allergic angio‐oedema is not supported by our findings.
- Published
- 2018
13. Streptococcus gallolyticus subsp gallolyticus endocarditis isolate interferes with coagulation and activates the contact system
- Author
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Shaynoor Dramsi, Juliane Köhler, Sonja Oehmcke-Hecht, Bernd Kreikemeyer, Julia Isenring, Marcus Frank, Camille Danne, Masanobu Nakata, Pierre Renault, Christoph Jans, Oehmcke-Hecht, Sonja, University of Rostock, Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), Osaka University, MICrobiologie de l'ALImentation au Service de la Santé (MICALIS), Institut National de la Recherche Agronomique (INRA)-AgroParisTech, Université Paris Saclay (COmUE), Institut Pasteur [Paris] (IP), Biologie des Bactéries pathogènes à Gram-positif - Biology of Gram-Positive Pathogens (BBPG+), Institut Pasteur [Paris] (IP)-Centre National de la Recherche Scientifique (CNRS), Deutsche Forschungsgemeinschaft (DFG) [OE 547/4-1], EU ERAfrica, Swiss Walter Hochstrasser Stiftung, Institut Pasteur [Paris], and Institut Pasteur [Paris]-Centre National de la Recherche Scientifique (CNRS)
- Subjects
0301 basic medicine ,Microbiology (medical) ,Streptococcus gallolyticus ,030106 microbiology ,Immunology ,Contact system ,Virulence ,Streptococcus gallolyticus subsp. gallolyticus ,Biology ,Microbiology ,lcsh:Infectious and parasitic diseases ,03 medical and health sciences ,Streptococcal Infections ,parasitic diseases ,medicine ,Endocarditis ,lcsh:RC109-216 ,Streptococcus gallolyticus subspecies gallolyticus ,Microbiology and Parasitology ,Streptococcus ,contact system ,medicine.disease ,Microbiologie et Parasitologie ,3. Good health ,Streptococcus bovis ,030104 developmental biology ,Infectious Diseases ,[SDV.MP]Life Sciences [q-bio]/Microbiology and Parasitology ,Coagulation ,Infective endocarditis ,Bacteremia ,bradykinin ,endocarditis ,pili ,Parasitology ,Research Paper - Abstract
International audience; Streptococcus gallolyticus subsp. gallolyticus, formerly classified as S. bovis biotype I, is an increasing cause of bacteremia and infective endocarditis in the elderly. The physiopathology of infective endocarditis is poorly understood and involves immune and coagulation systems. In this study, we found that S. gallolyticus subsp. gallolyticus activates the human contact system, which in turn has two consequences: cleavage of high-molecular-weight kininogen (HK) resulting in release of the potent pro-inflammatory peptide bradykinin, and initiation of the intrinsic pathway of coagulation. S. gallolyticus subsp. gallolyticus was found to bind and activate factors of the human contact system at its surface, leading to a significant prolongation of the intrinsic coagulation time and to the release of bradykinin. High-affinity binding of factor XII to the bacterial Pil1 collagen binding protein was demonstrated with a K-D of 13 nM. Of note, Pil1 expression was exclusively found in S. gallolyticus subsp. gallolyticus, further supporting an essential contribution of this pilus in virulence.
- Published
- 2018
14. Effect of Bradykinin Postconditioning on Ischemic and Toxic Brain Damage
- Author
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Maria Lalkovicova, Jozef Burda, Viera Danielisová, and Petra Bonova
- Subjects
Male ,Post-conditioning ,Ischemia ,Intoxication ,Hippocampus ,Brain damage ,Pharmacology ,Bradykinin ,Neuroprotection ,Biochemistry ,Brain Ischemia ,Brain ischemia ,Cellular and Molecular Neuroscience ,Medicine ,Animals ,Rats, Wistar ,Hypoxia, Brain ,Ischemic Postconditioning ,Maze Learning ,Original Paper ,business.industry ,Dentate gyrus ,General Medicine ,medicine.disease ,Barnes maze ,Rats ,Neuroprotective Agents ,Toxic injury ,Anesthesia ,medicine.symptom ,Glutamate ,business - Abstract
Brain damage caused by ischemia or toxic agents leads in selectively vulnerable regions to apoptosis-like delayed neuronal death and can result in irreversible damage. Selectively vulnerable neurons of the CA1 area of hippocampus are particularly sensitive to ischemic damage. We investigated the effects of bradykinin (BR) postconditioning on cerebral ischemic and toxic injury. Transient forebrain ischemia was induced by four-vessel occlusion for 10 min and toxic injury was induced by trimethyltin (TMT, 8 µg/kg i.p.). BR as a postconditioner at a dose of 150 µg/kg was applied intraperitoneally 48 h after ischemia or TMT intoxication. Experimental animals were divided into groups according to the length of survival (short—3 and 7 days, and long—28 days survival) and according to the applied ischemic or toxic injury. Glutamate concentration was lowered in both CA1 and dentate gyrus areas of hippocampus after the application of BR postconditioning in both ischemic and toxic brain damage. The number of degenerated neurons in the hippocampal CA1 region was significantly lower in BR-treated ischemic and toxic groups compared to vehicle group. The behavioral test used in our experiments confirms also the memory improvement in conditioned animals. The rats’ ability to form spatial maps and learn was preserved, which is visible from our Barnes maze results. By using the methods of delayed postconditioning is possible to stimulate the endogenous protective mechanisms of the organism and induce the neuroprotective effect. In this study we demonstrated that BR postconditioning, if applied before the onset of irreversible neurodegenerative changes, induced neuroprotection against ischemic or toxic injury.
- Published
- 2015
15. Vasomotor Effects of Acetylcholine, Bradykinin, Noradrenaline, 5-Hydroxytryptamine, Histamine and Angiotensin II on the Mouse Basilar Artery
- Author
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Yutaka Watanabe, Takeshi Obi, Mitsuya Shiraishi, Atsushi Miyamoto, Emi Yamazaki-Himeno, Ha Thi Thanh Nguyen, and Md. Zahorul Islam
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Male ,medicine.medical_specialty ,Serotonin ,Vasodilator Agents ,Cerebral arteries ,Bradykinin ,Vasodilation ,Pharmacology ,receptor subtype ,Tissue Culture Techniques ,chemistry.chemical_compound ,Mice ,Norepinephrine ,Internal medicine ,medicine.artery ,medicine ,Basilar artery ,Animals ,Vasoconstrictor Agents ,vasodilator ,cerebral artery ,General Veterinary ,Full Paper ,business.industry ,Angiotensin II ,Acetylcholine ,Endocrinology ,medicine.anatomical_structure ,chemistry ,Vasoconstriction ,Basilar Artery ,Circulatory system ,vasoconstrictor ,business ,pA2 ,medicine.drug ,Artery - Abstract
Because of the very small internal diameter (0.09–0.14 mm) and length (4–5 mm) of the mouse basilar artery, little information has been available regarding its reactivity to intrinsic vasoactive substances, such as acetylcholine (ACh), bradykinin (BK), noradrenaline (NA), 5-hydroxytryptamine (5-HT), histamine (His) and angiotensin (Ang) II in vitro and the receptor subtypes involved. The basilar artery runs along the ventral aspect of the medulla oblongata and supplies the brain with blood in reptiles [33], birds [20] and mammals. The responsiveness of this artery seems to reflect changes in cerebral blood flow and local microvascular pressure. Species differences in the responsiveness of this artery to intrinsic vasoactive substances have been reported, and some are very unique and characteristic. For example, NA, a well-known vasoconstrictor, induces contraction of the basilar artery in dogs [26], monkeys [24], guinea pigs [7] and rabbits [8], whereas it induces relaxation in that of cattle [3] and pigs [16]. The intensity of relaxation in pigs is much greater than that in cattle, and this larger relaxation induced by NA is one of the characteristics of porcine basilar artery. In other case, BK, which is a well-known vasorelaxing factor, induces relaxation in human basilar artery, but induces very strong contraction in equine basilar artery [25]. The contraction induced by BK is greater than that induced by NA, His or 5-HT, and this is also one of the characteristics of the equine basilar artery. Differences in responsiveness to these vasoactive substances might be dependent on differences in the distribution of their receptor subtypes on smooth muscle or endothelial cells. To our knowledge, basilar arterial responsiveness to these vasoactive substances in one species of animal has never been similar to that of other species. Therefore, characterization of basilar arterial reactivity in different species of animal would appear to be useful for investigating evolutionary relationships among animals. Mice are widely considered to be a prime model of inherited human disease and share 99% of their genes with humans [28]. They are the most commonly used vertebrate species, because of their availability, size, low cost, ease of handling and high reproduction rate. The routine availability of mouse models of various cerebral circulatory disorders like Alzheimer’s disease, migraine and stroke (4) requires characterization of the regulation of basilar arterial tone. A study of basilar artery is important, because it is one of the major resistance vessels in the brain. In the present study, therefore, we attempted to clarify in detail the responsiveness of isolated mouse basilar arteries to ACh, BK, NA, 5-HT, His and Ang II and the receptor subtypes involved.
- Published
- 2014
16. Endothelin‐1 shifts the mediator of bradykinin‐induced relaxation from NO to H2O2 in resistance arteries from patients with cardiovascular disease
- Author
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Leurgans, Thomas M, Bloksgaard, Maria, Brewer, Jonathan R, Bagatolli, Luis A, Fredgart, Maise H, Rosenstand, Kristoffer, Hansen, Maria L, Rasmussen, Lars M, Irmukhamedov, Akhmadjon, and De Mey, Jo G R
- Subjects
Male ,Endothelin-1 ,Arteries ,Hydrogen Peroxide ,In Vitro Techniques ,Bradykinin ,Nitric Oxide ,Research Papers ,Bradykinin/pharmacology ,Cardiovascular Diseases/metabolism ,Arteries/drug effects ,Cardiovascular Diseases ,Nitric Oxide/metabolism ,Humans ,Female ,Endothelin-1/pharmacology ,Hydrogen Peroxide/metabolism ,Aged - Abstract
Background and Purpose We tested the hypothesis that in resistance arteries from cardiovascular disease (CVD) patients, effects of an endothelium-dependent vasodilator depend on the contractile stimulus. Experimental Approach Arteries dissected from parietal pericardium of cardiothoracic surgery patients were studied by myography and imaging techniques. Segments were sub-maximally contracted by K +, the TxA 2 analogue U46619 or endothelin-1 (ET-1). Key Results Relaxing effects of Na-nitroprusside were comparable, but those of bradykinin (BK) were bigger in the presence of ET-1 compared with K + or U46619. BK-induced relaxation was (i) abolished by L-NAME in K +-contracted arteries, (ii) partly inhibited by L-NAME in the presence of U46619 and (iii) not altered by indomethacin, L-NAME plus inhibitors of small and intermediate conductance calcium-activated K + channels, but attenuated by catalase, in ET-1-contracted arteries. This catalase-sensitive relaxation was unaffected by inhibitors of NADPH oxidases or allopurinol. Exogenous H 2O 2 caused a larger relaxation of ET-1-induced contractions than those evoked by K + or U46619 in the presence of inhibitors of other endothelium-derived relaxing factors. Catalase-sensitive staining of cellular ROS with CellROX Deep Red was significantly increased in the presence of both 1 μM BK and 2 nM ET-1 but not either peptide alone. Conclusions and Implications In resistance arteries from patients with CVD, exogenous ET-1 shifts the mediator of relaxing responses to the endothelium-dependent vasodilator BK from NO to H 2O 2 and neither NADPH oxidases, xanthine oxidase nor NOS appear to be involved in this effect. This might have consequences for endothelial dysfunction in conditions where intra-arterial levels of ET-1 are enhanced.
- Published
- 2016
17. Developmental acceleration of bradykinin-dependent relaxation by prenatal chronic hypoxia impedes normal development after birth
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Michael Francis, Lawrence D. Longo, Carla Blum-Johnston, William J. Pearce, Sean M. Wilson, Alexander Brunelle, Quintin Blood, Chelsea Wee, Arlin B. Blood, Richard B. Thorpe, Rachael Wilson, Monica Romero, and Mark S. Taylor
- Subjects
0301 basic medicine ,Pulmonary and Respiratory Medicine ,medicine.medical_specialty ,Arginine ,Nitric Oxide Synthase Type III ,Physiology ,Bradykinin ,Stimulation ,Vasodilation ,030204 cardiovascular system & hematology ,Pulmonary Artery ,Nitric Oxide ,Nitric oxide ,Contractility ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Physiology (medical) ,Internal medicine ,medicine ,Animals ,Hypoxia ,Sheep ,Cell Biology ,Hypoxia (medical) ,030104 developmental biology ,Endocrinology ,chemistry ,Call for Papers ,Endothelium, Vascular ,medicine.symptom - Abstract
Bradykinin-induced activation of the pulmonary endothelium triggers nitric oxide production and other signals that cause vasorelaxation, including stimulation of large-conductance Ca2+-activated K+(BKCa) channels in myocytes that hyperpolarize the plasma membrane and decrease intracellular Ca2+. Intrauterine chronic hypoxia (CH) may reduce vasorelaxation in the fetal-to-newborn transition and contribute to pulmonary hypertension of the newborn. Thus we examined the effects of maturation and CH on the role of BKCachannels during bradykinin-induced vasorelaxation by examining endothelial Ca2+signals, wire myography, and Western immunoblots on pulmonary arteries isolated from near-term fetal (∼140 days gestation) and newborn, 10- to 20-day-old, sheep that lived in normoxia at 700 m or in CH at high altitude (3,801 m) for >100 days. CH enhanced bradykinin-induced relaxation of fetal vessels but decreased relaxation in newborns. Endothelial Ca2+responses decreased with maturation but increased with CH. Bradykinin-dependent relaxation was sensitive to 100 μM nitro-l-arginine methyl ester or 10 μM 1 H-[1,2,4]oxadiazolo[4,3- a]quinoxalin-1-one, supporting roles for endothelial nitric oxide synthase and soluble guanylate cyclase activation. Indomethacin blocked relaxation in CH vessels, suggesting upregulation of PLA2pathways. BKCachannel inhibition with 1 mM tetraethylammonium reduced bradykinin-induced vasorelaxation in the normoxic newborn and fetal CH vessels. Maturation reduced whole cell BKCachannel α1-subunit expression but increased β1-subunit expression. These results suggest that CH amplifies the contribution of BKCachannels to bradykinin-induced vasorelaxation in fetal sheep but stunts further development of this vasodilatory pathway in newborns. This involves complex changes in multiple components of the bradykinin-signaling axes.
- Published
- 2015
18. Pharmacological modulation of secondary mediator systems–cyclic AMP and cyclic GMP–on inflammatory hyperalgesia
- Author
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Cunha, F Q, Teixera, M M, and Ferreira, S H
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Inflammation ,Male ,Oxadiazoles ,Sulfonamides ,Interleukin-6 ,Phosphodiesterase Inhibitors ,Tumor Necrosis Factor-alpha ,Dopamine ,Interleukin-8 ,Bradykinin ,Carrageenan ,Isoquinolines ,Second Messenger Systems ,Dinoprostone ,Pyrrolidinones ,Rats ,Hyperalgesia ,Quinoxalines ,Papers ,Cyclic AMP ,Animals ,Rats, Wistar ,Cyclic GMP ,Rolipram ,Interleukin-1 - Abstract
1. The objective of the present paper was to evaluate the relevance of neuronal balance of cyclic AMP and cyclic GMP concentration for functional regulation of nociceptor sensitivity during inflammation. 2. Injection of PGE2 (10-100 ng paw-1) evoked a dose-dependent hyperalgesic effect which was mediated via a cyclic AMP-activated protein kinase (PKA) inasmuch as hyperalgesia was blocked by the PKA inhibitor H89. 3. The PDE4 inhibitor rolipram and RP73401, but not PDE3 and PDE5 inhibitors potentiated the hyperalgesic effects of PGE2. The hyperalgesic effect of dopamine was also enhanced by rolipram. Moreover, rolipram significantly potentiated hyperalgesia induced by carrageenan, bradykinin, TNF alpha, IL-1 beta, IL-6 and IL-8. This suggests that neuronal cyclic AMP mediates the prostanoid and sympathetic components of mechanical hyperalgesia. Moreover, in the neuron cyclic AMP is mainly metabolized by PDE4. 4. To examine the role of the NO/cyclic GMP pathway in modulating mechanical hyperalgesia, we tested the effects of the soluble guanylate cyclase inhibitor, ODQ. This substance counteracts the inhibitory effects of the NO donor, SNAP, on the hyperalgesia induced by PGE2. 5. The ODQ potentiated hyperalgesia induced by carrageenan, bradykinin, TNF alpha, IL-1 beta, IL-6 and IL-8. In contrast, ODQ had no significant effect on the hyperalgesia induced by PGE2 and dopamine. This indicates that the hyperalgesic cytokines may activate soluble guanylate cyclase, which down-regulate the ability of these substances to cause hyperalgesia. This event appears not to be mediated by prostaglandin or dopamine. 6. In conclusion, the results presented in this paper confirm an association between (i) hyperalgesia and elevated levels of cyclic AMP as well as (ii) antinociception and elevated levels of cyclic GMP. The intracellular levels of cyclic AMP that enhance hyperalgesia are controlled by the PDE4 isoform and appear to result in activation of protein kinase A whereas the intracellular levels of cyclic GMP results from activation of a soluble guanylate cyclase.
- Published
- 1999
19. Serine proteases and protease-activated receptor 2 mediate the proinflammatory and algesic actions of diverse stimulants
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Cattaruzza, F, Amadesi, S, Carlsson, JF, Murphy, JE, Lyo, V, Kirkwood, K, Cottrell, GS, Bogyo, M, Knecht, W, and Bunnett, NW
- Subjects
Male ,Benzylamines ,Serine Proteinase Inhibitors ,Pain ,PAR-2 ,Mice, Transgenic ,Inbred C57BL ,Bradykinin ,Transgenic ,Cell Line ,Mice ,Formaldehyde ,2.1 Biological and endogenous factors ,Animals ,Receptor, PAR-2 ,Trypsin ,Pharmacology & Pharmacy ,Aetiology ,Inflammation ,Foot ,Pain Research ,Pharmacology and Pharmaceutical Sciences ,Research Papers ,Mice, Inbred C57BL ,Azetidines ,Female ,Chronic Pain ,Serine Proteases ,Oligopeptides ,Receptor - Abstract
Background and purposeAlthough serine proteases and agonists of protease-activated receptor 2 (PAR2) cause inflammation and pain, the spectrum of proteases that are activated by proinflammatory and algesic stimuli and their contribution to inflammatory pain are uncertain.Experimental approachEnzymic assays and selective inhibitors were used to characterize protease activity in mice after intraplantar injections of formalin, bradykinin, PAR2 activating peptide (AP) or vehicle. The capacity of these proteases and of recombinant mouse trypsin 4 to cleave fragments of PAR2 and to activate PAR2 in cell lines was determined. Protease inhibitors and par2 (-/-) mice were used to assess the contributions of proteases and PAR2 to pain and inflammation.Key resultsIntraplantar injection of formalin, bradykinin or PAR2-AP led to the activation of proteases that were susceptible to the serine protease inhibitor melagatran but resistant to soybean trypsin inhibitor (SBTI). Melagatran inhibited mouse trypsin 4, which degraded SBTI. Proteases generated in inflamed tissues cleaved PAR2-derived peptides. These proteases and trypsin 4 increased [Ca(2+) ]i in PAR2-transfected but not in untransfected cells, and melagatran suppressed this activity. Melagatran or PAR2 deletion suppressed oedema and mechanical hypersensitivity induced by intraplantar formalin, bradykinin and PAR2-AP, but had no effect on capsaicin-induced pain.Conclusions and implicationsDiverse proinflammatory and algesic agents activate melagatran-sensitive serine proteases that cause inflammation and pain by a PAR2-mediated mechanism. By inducing self-activating proteases, PAR2 amplifies and sustains inflammation and pain. Serine protease inhibitors can attenuate the inflammatory and algesic effects of diverse stimuli, representing a useful therapeutic strategy.
- Published
- 2014
20. Binding characteristics of [3H]-JSM10292: a new cell membrane-permeant non-peptide bradykinin B2 receptor antagonist
- Author
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Faussner, A, Schüssler, S, Feierler, J, Bermudez, M, Pfeifer, J, Schnatbaum, K, Tradler, T, Jochum, M, Wolber, G, and Gibson, C
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Ornithine ,Sulfonamides ,Cell Membrane Permeability ,Receptor, Bradykinin B2 ,Pyridones ,Swine ,Cell Membrane ,Guinea Pigs ,Bradykinin ,Research Papers ,Binding, Competitive ,Rats ,Macaca fascicularis ,Mice ,Dogs ,HEK293 Cells ,Bradykinin B2 Receptor Antagonists ,Mutation ,Quinolines ,Animals ,Humans ,Rabbits - Abstract
A (3) H-labelled derivative of the novel small-molecule bradykinin (BK) B(2) receptor antagonist JSM10292 was used to directly study its binding properties to human and animal B(2) receptors in intact cells and to closely define its binding site.Equilibrium binding, dissociation and competition studies with various B(2) receptor ligands and [(3) H]-JSM10292 were performed at 4°C and 37°C. The experiments were carried out using HEK293 cells stably (over)expressing wild-type and mutant B(2) receptors of human and animal origin.[(3) H]-JSM10292 bound to B(2) receptors at 4°C and at 37°C with the same high affinity. Its dissociation strongly depended on the temperature and increased when unlabelled B(2) receptor agonists or antagonists were added. [(3) H]-JSM10292 is cell membrane-permeant and thus also bound to intracellular, active B(2) receptors, as indicated by the different 'nonspecific' binding in the presence of unlabelled JSM10292 or of membrane-impermeant BK. Equilibrium binding curves with [(3) H]-JSM10292 and competition experiments with unlabelled JSM10292 and [(3) H]-BK showed a different affinity profile for the wild-type B(2) receptor in different species (man, cynomolgus, rabbit, mouse, rat, dog, pig, guinea pig). Characterization of B(2) receptor mutants and species orthologues combined with homology modelling, using the CXCR4 as template, suggests that the binding site of JSM10292 is different from that of BK but overlaps with that of MEN16132, another small non-peptide B(2) receptor ligand.[(3) H]-JSM10292 is a novel, cell membrane-permeant, high-affinity B(2) receptor antagonist that allows direct in detail studies of active, surface and intracellularly located wild-type and mutant B(2) receptors.
- Published
- 2012
21. Biochemical characterization of a novel high-affinity and specific plasma kallikrein inhibitor
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Kolte, D, Bryant, JW, Holsworth, D, Wang, J, Akbari, P, Gibson, GW, and Shariat-Madar, Z
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Inflammation ,Lipopolysaccharides ,Kininogen, High-Molecular-Weight ,Aminopyridines ,Endothelial Cells ,Bradykinin ,Nitric Oxide ,Research Papers ,Epoprostenol ,Rats ,Substrate Specificity ,Kinetics ,Phenylephrine ,Animals ,Humans ,Aminobenzoates ,Enzyme Inhibitors ,Cells, Cultured ,Plasma Kallikrein ,Muscle Contraction ,Signal Transduction - Abstract
Kallikrein acts on high molecular weight kininogen (HK) to generate HKa (cleaved HK) and bradykinin (BK). BK exerts its effects by binding to B(2) receptors. The activation of B(2) receptors leads to the formation of tissue plasminogen activator, nitric oxide (NO) and prostacyclin (PGI(2) ). An elevated kallikrein-dependent pathway has been linked to cardiovascular disease risk. The aim of this study was to investigate whether our novel plasma kallikrein inhibitor abolishes kallikrein-mediated generation of BK from HK and subsequent BK-induced NO and PGI(2) formation, thereby influencing endothelial pathophysiology during chronic inflammatory diseases.Kinetic analysis was initially used to determine the potency of PF-04886847. Biochemical ligand binding assays, immunological methods and calcium flux studies were used to determine the selectivity of the kallikrein inhibitor. In addition, the effect of PF-04886847 on BK-induced relaxation of the rat aortic ring was determined in a model of lipopolysaccharide-induced tissue inflammation.Evidence was obtained in vitro and in situ, indicating that PF-04886847 is a potent and specific inhibitor of plasma kallikrein. PF-04886847 efficiently blocked calcium influx as well as NO and PGI(2) formation mediated through the BK-stimulated B(2) receptor signalling pathway. PF-04886847 blocked kallikrein-induced endothelial-dependent relaxation of isolated rat aortic rings pre-contracted with phenylephrine.PF-04886847 was shown to be the most potent small molecule inhibitor of plasma kallikrein yet described; it inhibited kallikrein in isolated aortic rings and cultured endothelial cells. Overall, our results indicate that PF-04886847 would be useful for the treatment of kallikrein-mediated inflammatory disorders.
- Published
- 2011
22. Comparison of the molecular interactions of two antagonists, MEN16132 or icatibant, at the human kinin B2 receptor
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Meini, S, Bellucci, F, Catalani, C, Cucchi, P, Giolitti, A, Giuliani, S, Quartara, L, Rotondaro, L, Zappitelli, S, and Maggi, CA
- Subjects
Models, Molecular ,Ornithine ,Sulfonamides ,Binding Sites ,Receptor, Bradykinin B2 ,CHO Cells ,In Vitro Techniques ,Bradykinin ,Research Papers ,Peptides, Cyclic ,Recombinant Proteins ,Kinetics ,Cricetulus ,Amino Acid Substitution ,Cricetinae ,Bradykinin B2 Receptor Antagonists ,Mutagenesis, Site-Directed ,Animals ,Humans ,Mutant Proteins ,Oligopeptides - Abstract
Icatibant is a well-known kinin B₂ receptor antagonist currently used for angiooedema attacks. MEN16132 is a non-peptide B₂ receptor antagonist, more potent and long lasting than icatibant in different models. Here we studied the reasons for these differences between the two antagonists.Rate of reversibility (over about 3 h) of the functional receptor blockade exerted by the antagonists was compared (inositol phosphates accumulation assay) in CHO cells expressing the human B₂ receptor and in human synovial cells. Antagonist pretreated cells were washed with medium and the time taken to restore bradykinin (BK) response measured. Antagonist affinity was measured by radioligand binding to wild type and mutated B₂ receptors.Recovery of BK-induced responses was slower in cells pretreated with MEN16132 than in those treated with icatibant. The affinity of icatibant (for the [³H]-BK or the B₂ receptor antagonist [³H]-MEN11270 binding site) was compared to that of MEN16132 using a panel of point-mutated receptors with mutations located at the transmembrane regions of the B₂ receptor, previously shown to decrease MEN16132 high affinity interaction. No consistent decrease of icatibant affinity was observed. From the different affinity of MEN16132 derivatives at wild type and W86A (transmembrane 2 region) receptors, and by evaluating its antagonist profile at the D266A/D284A double mutant receptor, a model of the MEN16132-B₂ receptor complex is proposed.MEN16132 dissociated from the B₂ receptor compartment more slowly than icatibant and interacted at a deeper level in transmembrane regions of the receptor.
- Published
- 2011
23. Anti-inflammatory synergy of MEN16132, a kinin B2 receptor antagonist, and dexamethasone in carrageenan-induced knee joint arthritis in rats
- Author
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Valenti, C, Giuliani, S, Cialdai, C, Tramontana, M, and Maggi, CA
- Subjects
Lipopolysaccharides ,Male ,Ornithine ,Sulfonamides ,Knee Joint ,Receptor, Bradykinin B2 ,Anti-Inflammatory Agents, Non-Steroidal ,Drug Synergism ,Bradykinin ,Carrageenan ,Research Papers ,Arthritis, Experimental ,Dexamethasone ,Injections, Intra-Articular ,Rats ,Bradykinin B2 Receptor Antagonists ,Animals ,Kallikreins ,Rats, Wistar ,Peroxidase - Abstract
Bradykinin, through its B(2) receptor, is involved in inflammatory processes related to arthropathies. In carrageenan and lipopolysaccharide (LPS)-induced arthritis in rat, the anti-inflammatory activity of MEN16132, a potent and selective kinin B(2) receptor antagonist, was compared with that of steroidal and nonsteroidal anti-inflammatory drugs. The interaction between MEN16132 and dexamethasone was also investigated.Drugs, alone or in combination, were injected into the knee joint 30min before intra-articular administration of carrageenan or LPS, in pentobarbital anaesthetized rats. Effects on incapacitation, oedema, neutrophil recruitment and kallikrein system activation, in the knee joint, were assessed.MEN16132 and dexamethasone (10-300µg per knee) dose-dependently reduced carrageenan-induced joint pain, oedema and neutrophil infiltration, reaching a maximal inhibition of about 50%. Dexketoprofen exerted a similar analgesic activity, whereas it did not affect the other inflammatory responses. MEN16132 showed a partial inhibition of LPS-induced joint pain, whereas dexamethasone produced a full analgesic effect. Combination of MEN16132 and dexamethasone showed a strong synergistic interaction in inhibiting both carrageenan and LPS-induced knee joint inflammation. Dexamethasone did not prevent the contact activation of prekallikrein by carrageenan and the subsequent release of kallikreins and bradykinin in the synovium.Steroids and kinin B(2) receptor antagonists appear to relieve arthritic symptoms induced by carrageenan or LPS and act synergistically to inhibit joint inflammation. This could have interesting therapeutic implications, possibly opening the way for combination therapies in the control of inflammatory arthropathies.
- Published
- 2010
24. Bradykinin-induced astrocyte–neuron signalling: glutamate release is mediated by ROS-activated volume-sensitive outwardly rectifying anion channels
- Author
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Liu, Hong-Tao, Akita, Tenpei, Shimizu, Takahiro, Sabirov, Ravshan Z, and Okada, Yasunobu
- Subjects
Patch-Clamp Techniques ,Hypertonic Solutions ,Models, Neurological ,Glutamic Acid ,Mice, Inbred Strains ,4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid ,Bradykinin ,Receptors, N-Methyl-D-Aspartate ,Ion Channels ,Mice ,Paracrine Communication ,Animals ,NADH, NADPH Oxidoreductases ,Calcium Signaling ,Enzyme Inhibitors ,Cell Shape ,Bradykinin Receptor Antagonists ,Cerebral Cortex ,Neurons ,Free Radical Scavengers ,Coculture Techniques ,Electric Stimulation ,Symposium Section Related Papers ,Hypotonic Solutions ,Phloretin ,Astrocytes ,Reactive Oxygen Species - Abstract
Glial cells release gliotransmitters which signal to adjacent neurons and glial cells. Previous studies showed that in response to stimulation with bradykinin, glutamate is released from rat astrocytes and causes NMDA receptor-mediated elevation of intracellular Ca(2+) in adjacent neurons. Here, we investigate how bradykinin-induced glutamate release from mouse astrocytes signals to neighbouring neurons in co-cultures. Astrocyte-to-neuron signalling and bradykinin-induced glutamate release from mouse astrocytes were both inhibited by the anion channel blocker 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid (DIDS) and phloretin. Glutamate release was also sensitive to 4-(2-Butyl-6,7-dichlor-2-cyclopentylindan-1-on-5-yl) oxybutyric acid (DCPIB), a specific blocker of the volume-sensitive outwardly rectifying anion channel (VSOR). Astrocytes, but not neurons, responded to bradykinin with activation of whole-cell Cl- currents. Although astrocytes stimulated with bradykinin did not undergo cell swelling, the bradykinin-activated current exhibited properties typical of VSOR: outward rectification, inhibition by osmotic shrinkage, sensitivity to DIDS, phloretin and DCPIB, dependence on intracellular ATP, and permeability to glutamate. Bradykinin increased intracellular reactive oxygen species (ROS) in mouse astrocytes. Pretreatment of mouse astrocytes with either a ROS scavenger or an NAD(P)H oxidase inhibitor blocked bradykinin-induced activation of VSOR, glutamate release and astrocyte-to-neuron signalling. By contrast, pretreatment with BAPTA-AM or tetanus neurotoxin A failed to suppress bradykinin-induced glutamate release. Thus, VSOR activated by ROS in mouse astrocytes in response to stimulation with bradykinin, serves as the pathway for glutamate release to mediate astrocyte-to-neuron signalling. Since bradykinin is an initial mediator of inflammation, VSOR might play a role in glia-neuron communication in the brain during inflammation.
- Published
- 2009
25. Bradykinin regulates human colonic ion transport in vitro
- Author
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Baird, A W, Skelly, M M, O'Donoghue, D P, Barrett, K E, and Keely, S J
- Subjects
Ion Transport ,Dose-Response Relationship, Drug ,Receptor, Bradykinin B2 ,Colon ,Vasodilator Agents ,Epithelial Cells ,Bradykinin ,Research Papers ,Dinoprostone ,Enteric Nervous System ,Cell Line ,Chlorides ,Bradykinin B2 Receptor Antagonists ,Humans - Abstract
Kinins are acknowledged as important regulators of intestinal function during inflammation; however, their effects on human intestinal ion transport have not been reported. Here, we used muscle-stripped human colonic tissue and cultured T(84)-cell monolayers to study bradykinin (BK) actions on human intestinal ion transport.Ion transport was measured as changes in short-circuit current (I(sc)) across colonic epithelia mounted in Ussing chambers.In intact tissue, there was a distinct polarity to BK-elicited I(sc) responses. Whereas basolateral BK stimulated sustained responses (EC(50)=0.5+/-0.1 microM), those to apical BK were more rapid and transient (EC(50)=4.1+/-1.2 nM). In T(84) cells, responses to both apical and basolateral BK were similar to those seen upon apical addition to intact tissues. Cross-desensitization between apical and basolateral domains was not observed. BK-induced responses were largely due to Cl(-) secretion as shown by their sensitivity to bumetanide and removal of Cl(-) from the bathing solution. Studies using selective agonists and antagonists indicate responses to BK are mediated by B(2) receptors. Finally, responses to basolateral BK in intact tissues were inhibited by tetrodotoxin (1 microM), atropine (1 microM), capsaicin (100 microM) and piroxicam (10 microM). BK-stimulated prostaglandin (PG)E(2) release from colonic tissue.BK stimulates human colonic Cl(-) secretion by activation of apical and basolateral B(2) receptors. Responses to apical BK reflect a direct action on epithelial cells, whereas those to basolateral BK are amplified by stimulation of enteric nerves and PG synthesis.
- Published
- 2008
26. Retinal plasma extravasation in streptozotocin-diabetic rats mediated by kinin B1 and B2 receptors
- Author
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Abdouh, M, Talbot, S, Couture, R, and Hasséssian, H M
- Subjects
Male ,Dose-Response Relationship, Drug ,Receptor, Bradykinin B2 ,Reverse Transcriptase Polymerase Chain Reaction ,Diamines ,Bradykinin ,Receptor, Bradykinin B1 ,Research Papers ,Antioxidants ,Retina ,Acetylcysteine ,Diabetes Mellitus, Experimental ,Rats ,Oxidative Stress ,Plasma ,Blood-Retinal Barrier ,Quinolines ,Animals ,Edema ,Benzothiazoles ,RNA, Messenger ,Organic Chemicals ,Rats, Wistar ,Evans Blue - Abstract
We investigated whether or not kinin receptors play a role in diabetic blood-retinal barrier breakdown, which is a leading cause of vision loss.Blood-retinal barrier breakdown was quantified using Evans blue, and expression of kinin B(1) receptor mRNA was measured using quantitative reverse transcrition-PCR. Diabetic rats (streptozotocin (STZ), 65 mg kg(-1)) received a single intraocular injection of bradykinin (BK) or des-Arg(9)-BK, alone, or in combination with antagonists for B(1) (des-Arg(10)-Hoe140, R-715) and/or B(2) (Hoe140) receptors, given intraocularly or intravenously (i.v.).In control rats, BK (0.1-10 nmol) dose-dependently increased plasma extravasation, which was inhibited by Hoe140 (0.2 nmol), whereas des-Arg(9)-BK (0.1 and 1 nmol) was without effect. B(1) receptor mRNA was markedly increased in retinas of diabetic rats, and this was prevented by N-acetyl-L-cysteine (1 g kg(-1) day(-1) for 7 days). Plasma extravasation in retinas of STZ-diabetic rats was higher than in controls and enhanced by des-Arg(9)-BK. Response to des-Arg(9)-BK was inhibited by intraocular or i.v. injection of B(1) receptor antagonists. Diabetes-induced plasma extravasation was inhibited only by a combination of des-Arg(10)-Hoe140 and Hoe 140 (100 nmol kg(-1), i.v. 15 min earlier) or by R-715 (1 micromol kg(-1), i.v.) injected daily for 7 days.Kinin B(1) receptors are upregulated in retinas of STZ-diabetic rats through a mechanism involving oxidative stress. Both kinin B(1) and B(2) receptors contribute to increased plasma extravasation in diabetic retinopathy. Chronic inhibition of both kinin receptors, possibly with antioxidant adjuvants, may be a novel therapeutic strategy for diabetic retinopathy.
- Published
- 2008
27. Effect of bradykinin metabolism inhibitors on evoked hypotension in rats: rank efficacy of enzymes associated with bradykinin-mediated angioedema
- Author
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Fryer, R M, Segreti, J, Banfor, P N, Widomski, D L, Backes, B J, Lin, C W, Ballaron, S J, Cox, B F, Trevillyan, J M, Reinhart, G A, and von Geldern, T W
- Subjects
Male ,Dose-Response Relationship, Drug ,Pyridines ,Thiazepines ,Drug Evaluation, Preclinical ,Angiotensin-Converting Enzyme Inhibitors ,Bradykinin ,Research Papers ,Aminopeptidases ,Rats ,Rats, Sprague-Dawley ,Lisinopril ,Indans ,Animals ,Neprilysin ,Angioedema ,Enzyme Inhibitors ,Hypotension ,Propionates ,Peptides - Abstract
Inhibition of bradykinin metabolizing enzymes (BMEs) can cause acute angioedema, as demonstrated in a recent clinical trial in patients administered the antihypertensive, omapatrilat. However, the relative contribution of specific BMEs to this effect is unclear and confounded by the lack of a predictive pre-clinical model of angioedema.Rats were instrumented to record blood pressure and heart rate; inhibitors were infused for 35 min and bradykinin was infused during the last 5 min to elicit hypotension, as a functional marker of circulating bradykinin and relative angioedema risk.In the presence of omapatrilat bradykinin produced dose-dependent hypotension, an effect abolished by B(2) blockade. In the presence of lisinopril (ACE inhibitor), but not candoxatril (NEP inhibitor) or apstatin (APP inhibitor), bradykinin also elicited hypotension. Lisinopril-mediated hypotension was unchanged with concomitant blockade of NEP or NEP/DPPIV (candoxatril+A-899301). However, hypotension was enhanced upon concomitant blockade of APP and further intensified in the presence of NEP inhibition to values not different from omapatrilat alone.We demonstrated that bradykinin is degraded in vivo with an enzyme rank-efficacy of ACEAPPNEP or DPPIV. These results suggest the effects of omapatrilat are mediated by inhibition of three BMEs, ACE/APP/NEP. However, dual inhibition of ACE/NEP or ACE/NEP/DPPIV elicits no increased risk of angioedema compared to ACE inhibition alone. Thus, novel BME inhibitors must display no activity against APP to avoid angioedema risk due to high prevalence of ACE inhibitor therapy in patients with diabetes and cardiovascular disease.
- Published
- 2007
28. Therapeutic concentrations of raloxifene augment nitric oxide-dependent coronary artery dilatation in vitro
- Author
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Leung, F P, Yung, L M, Leung, H S, Au, C L, Yao, X, Vanhoutte, P M, Laher, I, and Huang, Y
- Subjects
Estradiol ,Nitric Oxide Synthase Type III ,Swine ,Vasodilator Agents ,Estrogen Antagonists ,In Vitro Techniques ,Bradykinin ,Nitric Oxide ,Research Papers ,Coronary Vessels ,Muscle, Smooth, Vascular ,Vasodilation ,Raloxifene Hydrochloride ,Animals ,Fulvestrant - Abstract
Raloxifene improves cardiovascular function. This study examines the hypothesis that therapeutic concentrations of raloxifene augment endothelium-dependent relaxation via up-regulation of eNOS expression and activity in porcine coronary arteries.Isometric tension was measured in rings from isolated arteries. Intracellular Ca(2+) concentrations ([Ca(2+)](i)) in arterial endothelial cells were detected by Ca(2+) fluorescence imaging. Phosphorylation of eNOS at Ser-1177 was assayed by Western blot analysis.In arterial rings pre-contracted with 9,11-dideoxy-11alpha,9alpha-epoxy-methano-prostaglandin F(2alpha) (U46619), treatment with raloxifene (1-3 nM) augmented bradykinin- or substance P-induced relaxation and this effect was antagonized by ICI 182,780, an estrogen receptor antagonist. The enhanced relaxation was abolished in rings treated with inhibitors of nitric oxide/cyclic GMP-dependent dilation, N(G)-nitro-L-arginine methyl ester (L-NAME) plus 1H-[1,2,4]oxadizolo[4,3-a]quinoxalin-1-one (ODQ). In contrast, effects of raloxifene were unaffected after inhibition of endothelium-derived hyperpolarizing factors by charybdotoxin plus apamin. Raloxifene (3 nM) did not influence endothelium-independent relaxation to sodium nitroprusside. 17beta-Estradiol (3-10 nM) also enhanced bradykinin-induced relaxation, which was inhibited by ICI 182,780. Treatment with raloxifene (3 nM) did not affect bradykinin-stimulated rise in endothelial cell [Ca(2+)](i). Raloxifene, 17beta-estradiol, and bradykinin increased eNOS phosphorylation at Ser-1177 and ICI 182,780 prevented effects of raloxifene or 17beta-estradiol but not that of bradykinin. Raloxifene had neither additive nor antagonistic effects on 17beta-estradiol-induced eNOS phosphorylation.Raloxifene in therapeutically relevant concentrations augmented endothelial function in porcine coronary arteries in vitro through ICI 182,780-sensitive mechanisms that were associated with increased phosphorylation of eNOS but independent of changes in endothelial cell [Ca(2+)](i).
- Published
- 2007
29. Characterization of kinin receptors in human cultured detrusor smooth muscle cells
- Author
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Bellucci, F, Cucchi, P, Santicioli, P, Lazzeri, M, Turini, D, and Meini, S
- Subjects
Male ,Ornithine ,MEN16132 ,interleukin-1β ,Inositol Phosphates ,Interleukin-1beta ,Urinary Bladder ,Bradykinin ,Receptor, Bradykinin B1 ,Dinoprostone ,Radioligand Assay ,human urinary bladder ,Humans ,tumour necrosis factor-α ,Cells, Cultured ,PLC activation ,Sulfonamides ,icatibant ,Muscle, Smooth ,Kallidin ,Middle Aged ,Transforming Growth Factor alpha ,Research Papers ,Bradykinin B1 Receptor Antagonists ,upregulation - Abstract
Kinins have an important role in inflammatory cystitis and in animal pathophysiological models, by acting on epithelium, fibroblasts, sensory innervation and smooth muscle. The aim of this study was to characterize the receptors responsible for direct motor responses induced by kinins on human detrusor.Human detrusor cells from biopsies were isolated and maintained in culture. B(1) and B(2) kinin receptors were characterized by means of radioligand and functional experiments (PI accumulation and PGE(2) release).[(3)H]-[desArg(9)]-Lys-BK and [(3)H]-BK saturation studies indicated receptor density (B(max)) and K (d) values of 19 or 113 fmol mg(-1), and 0.16 or 0.11 nM for the B(1) or B(2) receptors, respectively. Inhibition binding studies indicated the selectivity of the B(1) receptor antagonist [desArg(9)Leu(8)]-Lys-BK and of the B(2) receptor antagonists Icatibant and MEN16132. [DesArg(9)]-Lys-BK and BK induced PI accumulation with an EC(50) of 1.6 and 1.4 nM and different maximal responses (E(max) of [desArg(9)]-Lys-BK was 10% of BK). BK also induced prostaglandin E(2) release (EC(50) 2.3 nM), whereas no response was detected with the B(1) receptor agonist. The incubation of detrusor smooth muscle cells with interleukin 1beta (IL-1beta) or tumour necrosis factor-alpha (TNF-alpha) (10 ng ml(-1)) induced a time-dependent increase in radioligand-specific binding, which was greater for the B(1) than for the B(2) receptor.Human detrusor smooth muscle cells in culture retain kinin receptors, and represent a suitable model to investigate the mechanisms and changes that occur under chronic inflammatory conditions.
- Published
- 2007
30. Bradykinin modulates pacemaker currents through bradykinin B2 receptors in cultured interstitial cells of Cajal from the murine small intestine
- Author
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Choi, Seok, Park, Do Young, Yeum, Cheol Ho, Chang, In Youb, You, Ho Jin, Park, Chan Guk, Kim, Man Yoo, Kong, In Deok, So, Insuk, Kim, Ki Whan, and Jun, Jae Yeoul
- Subjects
Male ,Mice, Inbred BALB C ,Patch-Clamp Techniques ,Receptor, Bradykinin B2 ,Sodium ,Calcium-Transporting ATPases ,Bradykinin ,Immunohistochemistry ,Mice ,Biological Clocks ,Chloride Channels ,Papers ,Intestine, Small ,Animals ,Calcium ,Cyclooxygenase Inhibitors ,Female ,Enzyme Inhibitors ,Cells, Cultured ,Protein Kinase C ,Signal Transduction - Abstract
We studied the modulation of pacemaker activities by bradykinin in cultured interstitial cells of Cajal (ICC) from murine small intestine with the whole-cell patch-clamp technique. Externally applied bradykinin produced membrane depolarization in the current-clamp mode and increased tonic inward pacemaker currents in the voltage-clamp mode. Pretreatment with bradykinin B1 antagonist did not block the bradykinin-induced effects on pacemaker currents. However, pretreatment with bradykinin B2 antagonist selectively blocked the bradykinin-induced effects. Also, only externally applied selective bradykinin B2 receptor agonist produced tonic inward pacemaker currents and ICC revealed a colocalization of the bradykinin B2 receptor and c-kit immunoreactivities, but bradykinin B1 receptors did not localize in ICC. External Na(+)-free solution abolished the generation of pacemaker currents and inhibited the bradykinin-induced tonic inward current. However, a Cl(-) channel blocker (DIDS) did not block the bradykinin-induced tonic inward current. The pretreatment with Ca(2+)-free solution and thapsigargin, a Ca(2+)-ATPase inhibitor in endoplasmic reticulum, abolished the generation of pacemaker currents and suppressed the bradykinin-induced action. Chelerythrine and calphostin C, protein kinase C inhibitors or naproxen, an inhibitor of cyclooxygenase, did not block the bradykinin-induced effects on pacemaker currents. These results suggest that bradykinin modulates the pacemaker activities through bradykinin B2 receptor activation in ICC by external Ca(2+) influx and internal Ca(2+) release via protein kinase C- or cyclooxygenase-independent mechanism. Therefore, the ICC are targets for bradykinin and their interaction can affect intestinal motility.
- Published
- 2006
31. Kallidin-like peptide mediates the cardioprotective effect of the ACE inhibitor captopril against ischaemic reperfusion injury of rat heart
- Author
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Liu, Xiuxin, Lukasova, Martina, Zubakova, Radka, Lewicka, Sabina, and Hilgenfeldt, Ulrich
- Subjects
Male ,Captopril ,Angiotensin-Converting Enzyme Inhibitors ,Myocardial Reperfusion Injury ,Kallidin ,Bradykinin ,Nitric Oxide ,Rats ,Rats, Sprague-Dawley ,NG-Nitroarginine Methyl Ester ,Coronary Circulation ,Papers ,Ischemic Preconditioning, Myocardial ,Animals ,cardiovascular diseases ,Creatine Kinase ,circulatory and respiratory physiology - Abstract
1. The potential cardioprotective effect of ACE inhibitors has been attributed to the inhibition of bradykinin degradation. Recent data in rats documented a kallidin-like peptide, which mimics the cardioprotective effect of ischaemic preconditioning. This study investigates in isolated Langendorff rat heart the effect of the ACE inhibitor captopril, the role of bradykinin, kallidin-like peptide, and nitric oxide (NO). 2. The bradykinin level in the effluent of the control group was 14.6 pg ml(-1) and was not affected by captopril in the presence or absence of kinin B2-receptor antagonist, HOE140. 3. The kallidin-like peptide levels were approximately six-fold higher (89.8 pg ml(-1)) and increased significantly by treatment with captopril (144 pg ml(-1)), and simultaneous treatment with captopril and HOE140 (197 pg ml(-1)). 4. Following 30 min ischaemia in the control group, the creatine kinase activity increased from 0.4 to 53.4 U l(-1). In the captopril group and in the captopril+L-NAME group, the creatine kinase activity was significantly lower (18.5 and 22.8 U l(-1)). This beneficial effect of captopril was completely abolished by the kinin B2-receptor antagonist, HOE140, as well as by the kallidin antiserum. 5. Perfusion of the hearts with kallidin before the 30 min ischaemia, but not with bradykinin, yielded an approximately 50% reduction in creatine kinase activity after reperfusion. 6. Pretreatment with L-NAME alone and simultaneously with captopril, and with kallidin, respectively, suggests a kinin-independent action of NO before the 30 min ischaemia on coronary flow and a kinin-dependent action after ischaemia. 7. These data show that captopril increases kallidin-like peptide in the effluent. Kallidin-like peptide via kinin B2 receptor seems to be the physiological mediator of cardioprotective actions of captopril against ischaemic reperfusion injury. HOE140 as well as the kallidin antiserum abolished the cardioprotective effects of captopril.
- Published
- 2006
32. Bradykinin decreases K+ and increases Cl− conductances in vagal afferent neurones of the guinea pig
- Author
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Oh, Eun Joo and Weinreich, Daniel
- Subjects
Male ,Patch-Clamp Techniques ,Guinea Pigs ,Bradykinin ,Research Papers ,Membrane Potentials ,Trachea ,Chlorides ,Chloride Channels ,Potassium ,Animals ,Calcium ,Nodose Ganglion ,Neurons, Afferent ,Cells, Cultured - Abstract
Bradykinin (BK) is an inflammatory mediator that can excite and sensitize primary afferent neurones. The nature of the ionic channels underlying the excitatory actions of BK is still incompletely understood. Using whole-cell patch-clamp recording from acutely dissociated nodose ganglion neurones (NGNs) we have examined the ionic mechanism responsible for BK's excitatory effect. Bath-applied BK (0.1 microM) depolarized the membrane potential (29 +/- 3.1 mV, n= 7), evoked action potentials, and induced an inward ionic current (I(BK)) with two distinctive membrane conductances (g(m)). Initially, g(m) decreased; the ionic current associated with this g(m) had a reversal potential (E(rev)) value of -87 +/- 1.1 mV (n= 26), a value close to E(K) (-89 mV). Subsequently, g(m) increased; the ionic current associated with this g(m) had an estimated E(rev) of 49 +/- 4.3 mV (n= 23). When the second component was isolated from the first component, by replacing [K(+)](o) with Cs(+), E(rev) was 20 +/- 4.7 mV (n= 10). Replacing external NaCl with NMDG-Cl or choline-Cl, or reducing [Ca(2+)](o) did not significantly diminish I(BK). After replacing external NaCl with sodium isethionate, E(rev) for the second component shifted to 56 +/- 8.8 mV (n= 4), a value close to the E(Cl) (66 mV). The second component was inhibited by intracellular BAPTA or by bath application of niflumic acid (100 microM), a Ca(2+)-activated Cl(-) channel blocker. These results suggest that the first and second components of I(BK) are produced by a decrease in K(+) conductance and an increase in Ca(2+)-activated Cl(-) conductance, respectively. The BK-evoked Cl(-) conductance in NGNs may be the first demonstration of an inflammatory mediator exciting primary afferents via an anion channel.
- Published
- 2004
33. Correlation between brain bradykinin receptor binding sites and cardiovascular function in young and adult spontaneously hypertensive rats
- Author
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Brice Ongali, Gaétan Thibault, Maria M. Campos, Frank Cloutier, Witold Neugebauer, and Réjean Couture
- Subjects
Male ,medicine.medical_specialty ,Aging ,medicine.drug_class ,Bradykinin ,Blood Pressure ,Peptide hormone ,Cardiovascular System ,Rats, Inbred WKY ,chemistry.chemical_compound ,Bradykinin receptor binding ,Heart Rate ,Internal medicine ,Rats, Inbred SHR ,medicine ,Animals ,cardiovascular diseases ,Bradykinin receptor ,Receptor ,Bradykinin Receptor Antagonists ,Pharmacology ,Binding Sites ,business.industry ,Receptors, Bradykinin ,Antagonist ,Brain ,Kinin ,Receptor antagonist ,Rats ,Endocrinology ,chemistry ,Papers ,Hypertension ,cardiovascular system ,business ,circulatory and respiratory physiology - Abstract
Intracerebroventricular (i.c.v.) effects of bradykinin (BK) B(1) and B(2) receptor agonists and antagonists were assessed on mean arterial blood pressure (MAP) and heart rate (HR) in awake unrestrained spontaneously hypertensive rats (SHR, aged of 8 and 16 weeks) and age-matched Wistar Kyoto rats (WKY). Quantitative in vitro autoradiographic studies were also performed on the brain of both strains with specific radioligands for B(2) receptors [(125)I]HPP-Hoe 140 and B(1) receptors [(125)I]HPP-des-Arg(10) and Hoe140. MAP increased linearly with doses of BK (81-8100 pmol) and the amplitudes were significantly greater in SHR, particularly at 16 weeks. While BK evoked a negative linear trend on HR (bradycardia) in WKY, a positive one (tachycardia) was observed in adult SHR. In both strains, BK-induced pressor response was blocked by equimolar doses of B(2) receptor antagonist, D-Arg-[Hyp(3), Thi(5), D-Tic(7), Oic(8)]-BK (Hoe 140), but not by B(1) receptor antagonist, AcLys[D-betaNal(7), Ile(8)]des-Arg(9)-BK (R-715). B(1) receptor agonists (Sar-[D-Phe(8)]-des-Arg(9)-BK, des-Arg(9)-BK, des-Arg(10)-Kallidin) and antagonist (R-715 alone or with Hoe 140) had no or marginal effect on MAP and HR at doses up to 8100 pmol in SHR and WKY. Higher densities of specific [(125)I]HPP-Hoe 140 labelling were found in discrete brain areas of SHR, especially in regions associated with cardiovascular function. Low levels of [(125)I]HPP-[des-Arg(10)]-Hoe140 binding sites were seen in WKY and SHR, yet densities were significantly greater in midbrain and cortical regions of SHR aged of 16 weeks. Contrary to SHR, ageing caused a downregulation of B(2) and B(1) receptor binding sites in specific brain nuclei in WKY. It is concluded that the hypersensitivity of the pressor response to i.c.v. BK in SHR occurs during both the early and established phases of hypertension in parallel with the enhancement of B(2) receptor binding sites in various cardiovascular brain centres. In contrast, brain B(1) receptors do not seem to participate in the central pressor effects of kinins nor in the maintenance of hypertension in SHR.
- Published
- 2004
34. Subtypes of vagal afferent C-fibres in guinea-pig lungs
- Author
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Undem, B J, Chuaychoo, B, Lee, M-G, Weinreich, D, Myers, A C, and Kollarik, M
- Subjects
Male ,Patch-Clamp Techniques ,Calcitonin Gene-Related Peptide ,Guinea Pigs ,Action Potentials ,Bronchi ,In Vitro Techniques ,Substance P ,Bradykinin ,Adenosine Triphosphate ,Neurofilament Proteins ,Physical Stimulation ,Animals ,Lung ,Afferent Pathways ,Nerve Fibers, Unmyelinated ,Laryngeal Nerves ,Vagus Nerve ,respiratory system ,Research Papers ,Immunohistochemistry ,Electrophysiology ,Trachea ,Ganglia ,Nodose Ganglion ,Capsaicin - Abstract
An ex vivo, vagally innervated, lung preparation was used to address the hypothesis that vagal C-fibres comprise at least two distinct phenotypes. Histological and extracellular electrophysiological experiments revealed that vagal C-fibres innervating the pulmonary system are derived from cell bodies situated in two distinct vagal sensory ganglia. The jugular (superior) ganglion neurones project C-fibres to both the extrapulmonary airways (larynx, trachea and bronchus) and the lung parenchymal tissue. By contrast, C-fibres from nodose (inferior) neurones innervate primarily structures within the lungs. Histologically, nodose neurones projecting lung C-fibres were different from the jugular neurones in that they were significantly less likely to express neurokinins. The nerve terminals within the lungs of both nodose and jugular C-fibres responded with action potential discharge to capsaicin and bradykinin application, but only the nodose C-fibre population responded with action potential discharge to the P2X selective receptor agonist alpha,beta-methylene-ATP. Whole cell patch clamp recording of capsaicin-sensitive nodose and jugular ganglion neurones retrogradely labelled from the lung tissue revealed that, like the nerve terminals, lung specific nodose C-fibre neurones express functional P2X receptors, whereas lung specific jugular C-fibres do not. The data support the hypothesis that both neural crest-derived neurones (jugular ganglia) and placode-derived neurones (nodose ganglia) project C-fibres in the vagus, and that these two C-fibre populations represent distinct phenotypes.
- Published
- 2004
35. Contribution of vanilloid receptors to the overt nociception induced by B2 kinin receptor activation in mice
- Author
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Ferreira, Juliano, da Silva, Gisele L, and Calixto, João B
- Subjects
Male ,Mice ,Dose-Response Relationship, Drug ,Receptor, Bradykinin B2 ,Receptors, Drug ,Papers ,Bradykinin B2 Receptor Antagonists ,Animals ,lipids (amino acids, peptides, and proteins) ,Capsaicin ,Bradykinin ,Pain Measurement - Abstract
1. The vanilloid receptor (TRPV1) is viewed as a molecular integrator of several nociceptive stimuli. In the present study, we have investigated the role played by TRPV1 in the nociceptive response induced by the peripheral activation of kinin B(2) receptor in mice. 2. The intraplantar (i.pl.) administration of bradykinin (BK) and the selective B(2) agonist Tyr(8)-BK, or the vanilloid agonists resiniferatoxin and capsaicin, into the mouse paw induced a dose-related overt nociception of short duration. The B(2) receptor antagonist Hoe 140 inhibited BK-induced, but not capsaicin-induced, nociceptive response. On the other hand, the TRPV1 antagonist capsazepine inhibited both capsaicin- and BK-mediated nociception. 3. Repeated injections of BK or capsaicin produced desensitization to their nociceptive response. Capsaicin desensitization greatly reduced BK-induced nociception, but in contrast, the desensitization to BK increased the capsaicin response. 4. Administration of low doses of capsaicin or acidified saline did not produce nociception when administered alone, but caused a pronounced effect when administered in association with a subthreshold dose of BK. Moreover, the degeneration of the subset of primary afferent fibers, sensitive to capsaicin, abolished both capsaicin- and BK-induced nociception. 5. The inhibition of phospholipase C (PLC), protein kinase C or phospholipase A(2) markedly decreased the nociception caused by BK, but not that of capsaicin. BK administration increased leukotriene B(4) levels in the injected paw. Likewise, BK-induced overt nociception was decreased by lipoxygenase (LOX) inhibition. 6. These results demonstrate that BK produces overt nociception mediated by TRPV1 receptor stimulation, via PLC pathway activation and LOX product formation.
- Published
- 2004
36. Activation of bronchopulmonary vagal afferent nerves with bradykinin, acid and vanilloid receptor agonists in wild-type and TRPV1−/− mice
- Author
-
Kollarik, M and Undem, B J
- Subjects
Male ,Mice, Knockout ,Afferent Pathways ,Nerve Fibers, Unmyelinated ,Dose-Response Relationship, Drug ,Polyunsaturated Alkamides ,musculoskeletal, neural, and ocular physiology ,Receptors, Drug ,Action Potentials ,Vagus Nerve ,Arachidonic Acids ,In Vitro Techniques ,Bradykinin ,Research Papers ,Mice, Inbred C57BL ,Mice ,nervous system ,Animals ,lipids (amino acids, peptides, and proteins) ,Lung ,psychological phenomena and processes ,Endocannabinoids - Abstract
The vanilloid receptor TRPV1 (formerly VR1) has been implicated in the activation of nociceptive sensory nerves by capsaicin, noxious heat, protons, bradykinin, cannabinoids such as anandamide, and certain metabolites of arachidonic acid. Using TRPV1 knockout mouse (TRPV1-/-) we address the question of whether TRPV1 is obligatory for action potential discharge in vagal C-fibre terminals evoked by capsaicin, anandamide, acid and bradykinin. The response of a defined subtype of the vagal afferent bronchopulmonary C-fibres (conduction velocity0.7 ms(-1)) to the putative TRPV1 activators was studied in vitro in the mouse isolated/perfused lung-nerve preparation. Capsaicin (1 microm) evoked action potential discharge of approximately 90% (28/31) of C-fibres in the TRPV1+/+ mice, but failed to activate bronchopulmonary C-fibres in TRPV1-/- animals (n = 10). Anandamide (3-100 microm) induced concentration-dependent activation of capsaicin-sensitive TRPV1+/+ C-fibres with a threshold of 3-10 microm, but failed to evoke substantive discharge in TRPV1-/- C-fibres. In the TRPV1+/+ mice, the B2 receptor-mediated activation by bradykinin (1 microm) was restricted to the capsaicin-sensitive C-fibres. Bradykinin was effective in evoking B2 receptor-mediated action potential discharge in TRPV1-/- C-fibres, but the response was significantly (P0.05) less persistent than in TRPV1+/+ C-fibres. Exposing the tissue to acid (pH = 5) excited both TRPV1+/+ and TRPV1-/- C-fibres. We conclude that TRPV1 is obligatory for vagal C-fibre activation by capsaicin and anandamide. By contrast, whereas TRPV1 may have a modulatory role in bradykinin and acid-induced activation of bronchopulmonary C-fibres, it is not required for action potential discharge evoked by these stimuli.
- Published
- 2003
37. Early upregulation of kinin B1 receptors in retinal microvessels of the streptozotocin-diabetic rat
- Author
-
Abdouh, Mohamed, Khanjari, Ashraf, Abdelazziz, Nadia, Ongali, Brice, Couture, Réjean, and Hasséssian, Haroutioun M
- Subjects
Male ,Dose-Response Relationship, Drug ,Microcirculation ,Retinal Vessels ,Bradykinin ,Receptor, Bradykinin B1 ,Retina ,Capillaries ,Diabetes Mellitus, Experimental ,Rats ,Up-Regulation ,Papers ,Animals ,Rats, Wistar - Abstract
(1) Retinal microvessel responses to kinin B1 and B2 receptor agonists and antagonists were investigated in streptozotocin (STZ)-diabetic rats and age-matched controls. In addition, quantitative in vitro autoradiography was performed on retinas from control and STZ-diabetic rats with radioligands specific for B2 ([125I]HPP-Hoe 140), and B1 receptors ([125I]HPP-[des-Arg10]-Hoe 140). (2) In control rats, the B2 receptor agonist bradykinin (BK, 0.1-50 nm) vasodilated retinal vessels in a concentration and time-dependent manner. This effect was completely blocked by the B2 receptor antagonist Hoe140 (1 microm). In contrast, the B1 receptor agonist des-Arg9-BK (0.1-50 nm) was without effect. (3) Des-Arg9-BK was able to produce a concentration-dependent vasodilatation as early as 4 days after STZ injection, and the effect of 1 nm des-Arg9-BK was inhibited by the B1 receptor antagonist des-Arg10-Hoe140 (1 microm). Low-level B1 receptor binding sites were detected in control rats, but densities were 256% higher in retinas from 4- to 21-day STZ-diabetic rats. (4) In control rats, the vasodilatation in response to 1 nm BK involved neither calcium influx nor nitric oxide (NO) as GdCl3 and l-NAME were without effect. However, the vasodilatation did involve intracellular calcium mobilization as well as products of the cyclooxygenase-2 (COX-2) pathway as 2,5-di-t-butylhydroquinone (BHQ), cADP ribose and l-745 337 inhibited this response. The vasodilatation response was blocked by trans-2-phenyl cyclopropylamine (TPC) demonstrating that prostacyclins mediate this response. (5) In STZ-diabetic rats, the vasodilatation in response to des-Arg9-BK involved both calcium influx and intracellular calcium mobilization from stores both IP3 sensitive and non-IP3 sensitive. Indeed, the effect was blocked by GdCl3, BHQ and cADP ribose. Furthermore, NO production and products of the COX-2 pathway including prostacyclin are involved as the response was inhibited by l-NAME, l-745 377 and TPC. (6) Vasodilatation in response to either 1 nm BK or 1 nm des-Arg9-BK were blocked by NF023 demonstrating that a Go/Gi G-protein transduces both these effects. (7) This is the first report on the retinal circulation which provides evidence for vasodilator B2 receptors and the upregulation of B1 receptors very early following induction of diabetes with STZ rats. These results suggest that kinin receptors may be potential targets for therapeutics to treat retinopathies.
- Published
- 2003
38. Evaluation of potassium ion as the endothelium-derived hyperpolarizing factor (EDHF) in the bovine coronary artery
- Author
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Nelli, Silvia, Wilson, William S, Laidlaw, Hilary, Llano, Andrea, Middleton, Susan, Price, Andrew G, and Martin, William
- Subjects
Dose-Response Relationship, Drug ,Drug Evaluation, Preclinical ,Cations, Monovalent ,In Vitro Techniques ,Bradykinin ,Coronary Vessels ,Vasodilation ,Biological Factors ,Papers ,cardiovascular system ,Potassium ,Animals ,Cattle ,Endothelium, Vascular ,Ouabain - Abstract
1. This study explored the role of the potassium ion in endothelium-derived hyperpolarizing factor (EDHF)-mediated vasodilatation in the bovine coronary artery. 2. Bradykinin-induced, EDHF-mediated vasodilatation was blocked by the Na(+)-K(+) ATPase inhibitor, ouabain (1 micro M), in a time-dependent manner, with maximal blockade seen after 90 min. In contrast, the K(IR) channel inhibitor, Ba(2+) (30 micro M), had no effect. 3. When the potassium content of the bathing solution was increased in a single step from 5.9 to 7-19 mM, powerful vasodilatation (max. 75.9+/-3.6%) was observed. Vasodilatation was transient and, consequently, cumulative addition of potassium produced little vasodilatation, with vasoconstriction predominating at the higher concentrations. 4. The magnitude of potassium-induced vasodilatation was similar in endothelium-containing and endothelium-denuded rings, and was unaffected by Ba(2+) (30 micro M), but abolished by ouabain (1 micro M). 5. Ouabain (1 micro M, 90 min) powerfully blocked bradykinin-induced, nitric oxide-mediated vasodilatation as well as that induced by the nitrovasodilator, glyceryl trinitrate, but that induced by the K(ATP) channel opener, levcromakalim, was hardly affected. 6. Thus, activation of Na(+)-K(+) ATPase is likely to be involved in the vasodilator responses of the bovine coronary artery to both nitric oxide and EDHF. These findings, together with the ability of potassium to induce powerful, ouabain- but not Ba(2+)-sensitive, endothelium-independent vasodilatation, are consistent with this ion contributing to the EDHF response in this tissue.
- Published
- 2003
39. Effect of a kinin B2 receptor antagonist on LPS- and cytokine-induced neutrophil migration in rats
- Author
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Santos, Danielle R, Calixto, João B, and Souza, Glória E P
- Subjects
Lipopolysaccharides ,Male ,Injections, Intradermal ,Receptor, Bradykinin B2 ,Neutrophils ,Tumor Necrosis Factor-alpha ,Bradykinin ,Receptor, Bradykinin B1 ,Rats ,Bradykinin B1 Receptor Antagonists ,Chemotaxis, Leukocyte ,Polysaccharides ,Papers ,Bradykinin B2 Receptor Antagonists ,Selectins ,Animals ,Rats, Wistar ,Interleukin-1 - Abstract
1 This study examines the involvement of kinins in neutrophil migration into rat subcutaneous air pouches triggered by lipopolysaccharide (LPS), as well as the putative roles played by kinin B(1) and B(2) receptors, tumour necrosis factor alpha (TNF-alpha), interleukin-1 beta (IL-1beta) and selectins in this response. 2 LPS (5 ng to 10 micro g cavity(-1)) injected into the 6-day-old pouch induced a dose- and time-dependent neutrophil migration which peaked between 4 and 6 h, and was maximal following the dose of 100 ng cavity(-1) (saline: 0.46+/-0.1; LPS: 43+/-3.70 x 10(6) cells cavity(-1) at 6 h). 3 Bradykinin (BK) (600 nmol) injected into the pouch of saline-treated rats induced only modest neutrophil migration (0.73+/-0.16 x 10(6) cells cavity(-1)). A more robust response to BK (3.2+/-0.25 x 10(6) cells cavity(-1)) was seen in animals pretreated with captopril, but this was still smaller than the responses to IL-1beta or TNF-alpha (15 pmol: 23+/-2.2 x 10(6) and 75 pmol: 29.5+/-2 x 10(6) cells cavity(-1), respectively). Nevertheless, the B(1) agonist des-Arg(9)-BK (600 nmol) failed to induce neutrophil migration. 4 HOE-140 (1 and 2 mg kg(-1)), a B(2) receptor antagonist, reduced LPS-induced neutrophil migration. HOE-140 also reduced the neutrophil migration induced by BK, but had no effect on the migration promoted by IL-1beta or TNF-alpha. des-Arg(9)-[Leu(8)]-BK, B(1) receptor antagonist was ineffective in changing neutrophil migration caused by any of these stimuli. 5 Neutrophil migration induced by LPS or BK was reduced by interleukin-1 receptor antagonist (IL-1ra) (1 mg kg(-1)), sheep anti-rat TNF serum (anti-TNF serum) (0.3 ml cavity(-1)), and the nonspecific selectin inhibitor fucoidin (10 mg kg(-1)). 6 TNF-alpha levels in the pouch fluid were increased by LPS or BK injection, peaking at 0.5-1 h and gradually declining thereafter up to 6 h. IL-1beta levels increased steadily throughout the 6 h period. HOE-140 markedly inhibited the rise in IL-1beta and TNF-alpha levels in pouch fluid triggered by both stimuli. 7 These results indicate that BK participates importantly in selectin-dependent neutrophil migration into the air pouch triggered by LPS in the rat, by stimulating B(2) receptors coupled to synthesis/release of TNF-alpha and IL-1beta.
- Published
- 2003
40. Differential effects of ascorbate on endothelium-derived hyperpolarizing factor (EDHF)-mediated vasodilatation in the bovine ciliary vascular bed and coronary artery
- Author
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Fiona J. Dowell, William Martin, Silvia Nelli, William S. Wilson, and Alister J. McNeish
- Subjects
Endothelium-derived hyperpolarizing factor ,Cromakalim ,Endothelium ,Bradykinin ,Collateral Circulation ,Vasodilation ,Pharmacology ,Ciliary Arteries ,Aqueous Humor ,chemistry.chemical_compound ,Coronary circulation ,Biological Factors ,Potassium Channels, Calcium-Activated ,Ciliary body ,medicine.artery ,Coronary Circulation ,medicine ,Animals ,Dose-Response Relationship, Drug ,business.industry ,Ciliary Body ,Ciliary arteries ,Acetylcholine ,medicine.anatomical_structure ,chemistry ,Anesthesia ,Papers ,cardiovascular system ,Ascorbate Oxidase ,Cattle ,Nitric Oxide Synthase ,business ,circulatory and respiratory physiology - Abstract
The ability of ascorbate to inhibit endothelium-derived hyperpolarizing factor (EDHF)-mediated vasodilatation was compared in the bovine perfused ciliary vascular bed and isolated rings of coronary artery. Acetylcholine-induced, EDHF-mediated vasodilatation of the ciliary circulation was blocked following inclusion of ascorbate (50 μM, 120 min) in the perfusion fluid. The blockade was highly selective since ascorbate had no effect on the vasodilator actions of the KATP channel opener, levcromakalim, nor on the tonic vasodepressor action of basally released nitric oxide. The possibility that concentration of ascorbate by the ciliary body was a prerequisite for blockade to occur was ruled out, since EDHF was still blocked when the anterior and posterior chambers were continuously flushed with Krebs solution or when both the aqueous and vitreous humour were drained. Ascorbate at 50 μM failed to affect bradykinin- or acetylcholine-induced, EDHF-mediated vasodilatation in rings of bovine coronary artery. Raising the concentration to 3 mM did produce blockade of EDHF, but this was nonselective, since vasodilator responses to endothelium-derived nitric oxide were also inhibited. Thus, ascorbate (50 μM) is not a universal blocker of EDHF. Whether its ability to block in the bovine ciliary circulation, but not in the coronary artery, is due to differences in the nature of EDHF at the two sites, differences in vessel size (resistance arterioles versus conduit artery), the presence or absence of flow, or to some other factor remains to be determined. British Journal of Pharmacology (2003) 138, 1172–1180. doi:10.1038/sj.bjp.0705143
- Published
- 2003
41. Charybdotoxin-sensitive small conductance KCa channel activated by bradykinin and substance P in endothelial cells
- Author
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Sollini, M, Frieden, M, and Bény, J-L
- Subjects
Patch-Clamp Techniques ,Potassium Channels ,Charybdotoxin ,Small-Conductance Calcium-Activated Potassium Channels ,Swine ,Substance P ,Bradykinin ,Coronary Vessels ,Membrane Potentials ,Potassium Channels, Calcium-Activated ,Apamin ,Papers ,Potassium Channel Blockers ,Animals ,Benzimidazoles ,Endothelium, Vascular ,Cells, Cultured - Abstract
1 In cultured porcine coronary artery endothelial cells, we have recently shown that substance P and bradykinin stimulated different types of Ca(2+)-dependent K(+) (K(Ca)) current. A large part of this current was insensitive to iberiotoxin and apamin. The aim of the present study was to characterize the K(Ca) channel responsible for this current. 2 In cell-attached configuration and asymmetrical K(+) concentration, 100 nM bradykinin or substance P activated a 10 pS K(+) channel. In inside-out configuration, the channel was half-maximally activated by 795 nM free Ca(2+). 3 Apamin (1 micro M) added to the pipette solution failed to inhibit the channel activity while charybdotoxin (50 nM), completely blocked it. Perfusion at the intracellular face of the cell, of an opener of intermediate conductance K(Ca) channel, 500 micro M 1-ethyl-benzimidazolinone (1-EBIO) increased the channel activity by about 4.5 fold. 4 In whole-cell mode, bradykinin and substance P stimulated an outward K(+) current of similar amplitude. Charybdotoxin inhibited by 75% the bradykinin-induced current and by 80% the substance P-induced current. Charybdotoxin plus iberiotoxin (50 nM each) inhibited by 97% the bradykinin-response. Charybdotoxin plus apamin did not increase the inhibition of the substance P-response obtained in the presence of charybdotoxin alone. 5 1-EBIO activated a transient outward K(+) current and hyperpolarized the membrane potential by about 13 mV. Charybdotoxin reduced the hyperpolarization to about 3 mV. 6 Taken together these results show that bradykinin and substance P activate a 10 pS K(Ca) channel, which largely contributes to the total K(+) current activated by these agonists. Despite its small conductance, this channel shares pharmacological characteristics with intermediate conductance K(Ca) channels.
- Published
- 2002
42. AT2 receptor-dependent vasodilation is mediated by activation of vascular kinin generation under flow conditions
- Author
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Jun, Katada and Masataka, Majima
- Subjects
Male ,endocrine system ,Receptor, Bradykinin B2 ,Kallikrein-Kinin System ,Vasodilator Agents ,Indomethacin ,In Vitro Techniques ,Bradykinin ,Receptor, Angiotensin, Type 2 ,Rats, Inbred BN ,Pressure ,Animals ,Humans ,Cyclooxygenase Inhibitors ,Bradykinin Receptor Antagonists ,Receptors, Angiotensin ,Kininogens ,Angiotensin II ,Mesenteric Arteries ,Rats ,Perfusion ,Vasodilation ,Papers ,Commentary ,cardiovascular system ,Kallikreins ,Vascular Resistance ,Endothelium, Vascular ,hormones, hormone substitutes, and hormone antagonists ,circulatory and respiratory physiology - Abstract
Physiological roles of angiotensin II type 2 receptor (AT(2)) are not well defined. This study was designed to investigate the mechanisms of AT(2)-dependent vascular relaxation by studying vasodilation in pressurized and perfused rat mesenteric arterial segments. Perfusion of angiotensin II in the presence of AT(1) antagonist elicited vascular relaxation, which was completely dependent on AT(2) receptors on endothelium. FR173657 (1 microM), a bradykinin (BK) B(2)-specific antagonist, significantly suppressed AT(2)-dependent vasodilation (maximum inhibition: 68.5% at 10 microM). Kininogen-deficient Brown Norway Katholiek rats showed a significant reduction in AT(2)-mediated vasodilatory response compared with normal wild-type Brown Norway rats. Indomethacin (1 microM), aprotinin (10 microM) and soybean trypsin inhibitor (10 microM) also reduced AT(2)-dependent vasodilation. Our results demonstrated that stimulation of AT(2) receptors caused a significant vasodilation through local production of BK in resistant arteries of rat mesentery in a flow-dependent manner. Such vasodilation counterbalances AT(1)-dependent vasoconstriction to regulate the vascular tone.
- Published
- 2002
43. Interactive contribution of NK1 and kinin receptors to the acute inflammatory oedema observed in response to noxious heat stimulation: studies in NK1 receptor knockout mice
- Author
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Rawlingson, Andrew, Gerard, Norma P, and Brain, Susan D
- Subjects
Mice, Knockout ,Quinuclidines ,Hot Temperature ,Time Factors ,Receptor, Bradykinin B2 ,Neutrophils ,Administration, Topical ,Receptors, Bradykinin ,Dermatitis ,Receptors, Neurokinin-1 ,Bradykinin ,Receptor, Bradykinin B1 ,Mice, Inbred C57BL ,Mice ,Piperidines ,Cell Movement ,Tachykinins ,Papers ,Injections, Intravenous ,Animals ,Edema ,Capsaicin ,Burns ,Bradykinin Receptor Antagonists - Abstract
1. Scald injury in Sv129+C57BL/6 mice induced a temperature and time dependent oedema formation as calculated by the extravascular accumulation of [(125)I]-albumin. Oedema formation was suppressed in NK(1) knockout mice compared to wildtypes at 10 (P0.01) and 30 min (P0.001). However, at 60 min a similar degree of extravasation was observed in the two groups. 2. Kinin B(1) (des-Arg(10) Hoe 140; 1 micromol kg(-1)) and B(2) (Hoe 140; 100 nmol kg(-1)) antagonists caused an inhibition of oedema in wildtype mice at 10 and 30 min (P0.001), but not at 60 min or at 30 min in NK(1) receptor knockout mice. 3. The inhibition of thermic oedema by des-Arg(10) Hoe 140 was reversed by des-Arg(9) bradykinin (0.1 micromol kg(-1); P0.01) and also observed with a second B(1) receptor antagonist (des-Arg(9) Leu(8) bradykinin; 3 micromol kg(-1); P0.01). Furthermore des-Arg(10) Hoe 140 had no effect on capsaicin (200 microg ear(-1)) ear oedema, but this was significantly reduced with Hoe 140 (P0.05). 4. Scalding induced a large neutrophil accumulation at 4 h, as assessed by myeloperoxidase assay (P0.001). This was not suppressed by NK(1) receptor deletion or kinin antagonists. 5. These results confirm an essential role for the NK(1) receptor in mediating the early, but not the delayed phase of oedema formation or neutrophil accumulation in response to scalding. The results also demonstrate a pivotal link between the kinins and sensory nerves in the microvascular response to burn injury, and for the first time show a rapid involvement of the B(1) receptor in murine skin.
- Published
- 2001
44. Apstatin, a selective inhibitor of aminopeptidase P, reduces myocardial infarct size by a kinin-dependent pathway
- Author
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Wolfrum, S, Richardt, G, Dominiak, P, Katus, H A, and Dendorfer, A
- Subjects
Male ,Receptor, Bradykinin B2 ,Myocardium ,Hemodynamics ,Myocardial Infarction ,Angiotensin-Converting Enzyme Inhibitors ,Blood Pressure ,Heart ,Kinins ,Bradykinin ,Aminopeptidases ,Rats ,Ramipril ,Heart Rate ,Papers ,Animals ,Protease Inhibitors ,Rats, Wistar ,Peptides ,Bradykinin Receptor Antagonists - Abstract
1. Inhibitors of the angiotensin converting enzyme (ACE) have been shown to exert their cardioprotective actions through a kinin-dependent mechanism. ACE is not the only kinin degrading enzyme in the rat heart. 2. Since aminopeptidase P (APP) has been shown to participate in myocardial kinin metabolism to the same extent as ACE, the aims of the present study were to investigate whether (a) inhibition of APP leads to a reduction of myocardial infarct size in a rat model of acute ischaemia and reperfusion, (b) reduction of infarct size is mediated by bradykinin, and (c) a combination of APP and ACE inhibition leads to a more pronounced effect than APP inhibition alone. 3. Pentobarbital-anaesthetized rats were subjected to 30 min left coronary artery occlusion followed by 3 h reperfusion. The APP inhibitor apstatin, the ACE-inhibitor ramiprilat, or their combination were administered 5 min before ischaemia. Rats receiving HOE140, a specific B(2) receptor antagonist, were pretreated 5 min prior to enzyme inhibitors. Myocardial infarct size (IS) was determined by tetrazolium staining and expressed as percentage of the area at risk (AAR). 4. IS/AAR% was significantly reduced in rats that received apstatin (18+/-2%), ramiprilat (18+/-3%), or apstatin plus ramiprilat (20+/-4%) as compared with those receiving saline (40+/-2%), HOE (43+/-3%) or apstatin plus HOE140 (49+/-4%). 5. Apstatin reduces IS in an in vivo model of acute myocardial ischaemia and reperfusion to the same extent than ramiprilat. Cardioprotection achieved by this selective inhibitor of APP is mediated by bradykinin. Combined inhibition of APP and ACE did not result in a more pronounced reduction of IS than APP-inhibition alone.
- Published
- 2001
45. Endothelium-dependent relaxation induced by cathepsin G in porcine pulmonary arteries
- Author
-
Glusa, Erika and Adam, Christine
- Subjects
Cathepsin G ,Serine Proteinase Inhibitors ,Heparin ,Swine ,Serine Endopeptidases ,Thrombin ,Proteins ,Suramin ,Pulmonary Artery ,Bradykinin ,Dinoprost ,Cathepsins ,Vasodilation ,Inhibitory Concentration 50 ,NG-Nitroarginine Methyl Ester ,Polydeoxyribonucleotides ,Papers ,Animals ,Humans ,Trypsin ,Endothelium, Vascular ,Cyclic GMP ,Serpins - Abstract
Serine proteinases elicit profound cellular effects in various tissues mediated by activation of proteinase-activated receptors (PAR). In the present study, we investigated the vascular effects of cathepsin G, a serine proteinase that is present in the azurophil granules of leukocytes and is known to activate several cells that express PARs. In prostaglandin F2alpha (3 microM)-precontracted rings from porcine pulmonary arteries with intact endothelium, cathepsin G caused concentration-dependent relaxant responses (pEC(50)=9.64+/-0.12). The endothelium-dependent relaxant effect of cathepsin G could also be demonstrated in porcine coronary arteries (pEC(50)=9.23+/-0.07). In pulmonary arteries the cathepsin G-induced relaxation was inhibited after blockade of nitric oxide synthesis by L-NAME (200 microM) and was absent in endothelium-denuded vessels. Bradykinin- and cathepsin G-induced relaxant effects were associated with a 5.7 fold and 2.4 fold increase in the concentration of cyclic GMP, respectively. Compared with thrombin and trypsin, which also produced an endothelium-dependent relaxation in pulmonary arteries, cathepsin G was 2.5 and four times more potent, respectively. Cathepsin G caused only small homologous desensitization. In cathepsin G-challenged vessels, thrombin was still able to elicit a relaxant effect. The effects of cathepsin G were blocked by soybean trypsin inhibitor (IC(50)=0.043 microg ml(-1)), suggesting that proteolytic activity is essential for induction of relaxation. Recombinant acetyl-eglin C proved to be a potent inhibitor (IC(50)=0.14 microg ml(-1)) of the cathepsin G effect, whereas neither indomethacin (3 microM) nor the thrombin inhibitor hirudin (5 ATU ml(-1)) elicited any inhibitory activity. Due to their polyanionic structure defibrotide (IC(50)=0.11 microg ml(-1)), heparin (IC(50)=0.48 microg ml(-1)) and suramin (IC(50)=1.85 microg ml(-1)) diminished significantly the relaxation in response to the basic protein cathepsin G. In conclusion, like thrombin and trypsin, cathepsin G is able to induce endothelium-dependent vascular relaxation. It can be released from activated leukocytes at sites of vascular injury and inflammation and, therefore, sufficiently high concentrations might be reached locally in the vascular space to induce vasodilatation.
- Published
- 2001
46. Endogenous opioids suppress activation of nociceptors by sub-nanomolar nicotine
- Author
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Miao, Frederick J-P, Benowitz, Neal L, and Levine, Jon D
- Subjects
Male ,Nicotine ,Time Factors ,Knee Joint ,Narcotic Antagonists ,Bradykinin ,Hexamethonium ,Rats, Sprague-Dawley ,Neurokinin-1 Receptor Antagonists ,Animals ,Neurons, Afferent ,Inflammation ,Analysis of Variance ,Dose-Response Relationship, Drug ,Naloxone ,Nociceptors ,Receptors, Neurokinin-1 ,Sciatic Nerve ,Naltrexone ,Rats ,Animals, Newborn ,Opioid Peptides ,Adrenal Medulla ,Papers ,Receptors, Opioid ,Capsaicin - Abstract
1. Nicotine can activate primary afferent nociceptors, one result of which is to increase neurogenic plasma extravasation. In this study we have demonstrated a novel proinflammatory effect of sub-nanomolar nicotine, mediated by peripheral action at sensory neurons. This action is normally masked by adrenal medulla-derived delta-opioid receptor agonists. 2. While neurogenic plasma extravasation in the knee joint of the rat was not increased by intra-articular perfusion of nicotine (10(-8) M), perfusion of nicotine, at concentrations as low as 10(-10) M, combined with naloxone to block opioid receptors (or naltrindole to block delta-opioid receptors) was able to enhance bradykinin-induced plasma extravasation. This pro-inflammatory effect of intra-articular nicotine was mimicked by subcutaneous nicotine which was abolished by intra-articularly-administered hexamethonium, a nicotinic receptor antagonist. 3. Following denervation of the adrenal medulla, intra-articular nicotine, alone at 10(-8) M, enhanced plasma extravasation, which was no longer enhanced by naloxone. 4. Destruction of primary afferents by neonatal treatment with capsaicin or blockade of sensory neurotransmitter by neurokinin-1 receptor antagonist RP-87,580 abolished the pro-inflammatory effect of nicotine. 5. The effect of nicotine we describe in promoting inflammation is exerted at extremely low concentrations and therefore could have relevance to smokers, patients receiving medicinal nicotine as therapy and even second-hand smokers. Since receptor mechanisms on peripheral terminals of nociceptors may also be present on central terminals, actions of the endogenous nicotinic agonist acetylcholine, at central terminals of primary afferents or at other sites in the central nervous system, may be similarly modulated by opioids.
- Published
- 2001
47. The polycationic aminoglycosides modulate the vasoconstrictive effects of endothelin: relevance to cerebral vasospasm
- Author
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Wickman, Grant, Nessim, Mourad A, Cook, David A, and Vollrath, Bozena
- Subjects
Male ,Indoles ,Bradykinin ,Peptides, Cyclic ,Muscle, Smooth, Vascular ,Dogs ,Kanamycin ,Isometric Contraction ,Polyamines ,Animals ,Vasospasm, Intracranial ,Pyrroles ,Cells, Cultured ,Protein Kinase C ,Dose-Response Relationship, Drug ,Endothelin-1 ,Neomycin ,Cerebral Arteries ,Polyelectrolytes ,Anti-Bacterial Agents ,Vasoconstriction ,Papers ,Streptomycin ,Tetradecanoylphorbol Acetate ,Female ,Gentamicins - Abstract
1. The vasoactive peptide endothelin (ET) has been implicated in the pathogenesis of cerebral vasospasm following subarachnoid haemorrhage. In these studies we investigated the involvement of protein kinase C (PKC) in sustained vasoconstriction induced by ET-1 in canine cerebral arteries. We also examined the ability of the aminoglycoside antibiotics to reverse the effects mediated by ET-1 in canine cerebrovascular smooth muscle cells (CVSMC). 2. The ET(A) receptor antagonist, BQ-123, showed a competitive inhibition of the ET-1 responses. 3. The vasoconstrictor action of both ET-1 (0.5 nM) and phorbol myristate acetate (PMA) (160 nM) was reversed by a selective PKC inhibitor, Ro-32-0432. 4. In cerebral arteries precontracted with ET-1 the aminoglycosides caused a concentration-dependent relaxation. The EC(50s) for the relaxation were as follows: 0.54+/-0.05, 0.63+/-0.01, 1.88+/-0.46 and 2.3+/-0.92 mM for gentamicin, neomycin, streptomycin and kanamycin, respectively. 5. Gentamicin caused a concentration-dependent decrease of the PMA-induced responses in calcium free medium. 6. PKC activity was elevated in CVSMC exposed to ET-1 (170%) and PMA (167%) for a period of time (60 min) corresponding to maximum tonic contraction induced by these agents in arterial rings. 7. The administration of the aminoglycosides to CVSMC, in concentrations corresponding to the EC(50s) from contractility studies, reduced the effects of both ET-1 and PMA on PKC activity to the levels not different from controls. 8. These results show that the aminoglycosides are able to inhibit sustained vasoconstriction induced by ET-1, an effect which is due, at least in part, to the inhibition of PKC.
- Published
- 2001
48. Signal transduction pathways involved in kinin B2 receptor-mediated vasodilation in the rat isolated perfused kidney
- Author
-
Bagaté, Karim, Grima, Michèle, Imbs, Jean-Louis, Jong, Wybren De, Helwig, Jean-Jacques, and Barthelmebs, Mariette
- Subjects
Male ,Nitric Oxide Synthase Type III ,Receptor, Bradykinin B2 ,Receptors, Drug ,In Vitro Techniques ,Bradykinin ,Nitroarginine ,Renal Circulation ,Biological Factors ,Animals ,Cytochrome P-450 Enzyme Inhibitors ,Cyclooxygenase Inhibitors ,Enzyme Inhibitors ,Rats, Wistar ,Receptors, Cannabinoid ,Bradykinin Receptor Antagonists ,Cannabinoids ,Receptors, Bradykinin ,Acetylcholine ,Rats ,Vasodilation ,Papers ,cardiovascular system ,Potassium ,Nitric Oxide Synthase ,Signal Transduction - Abstract
The signal transduction pathways involved in kinin B(2) receptor-related vasodilation were investigated in rat isolated perfused kidneys. During prostaglandin F(2alpha) or KCl-induced constriction, the vasodilator response to a selective B(2) receptor agonist, Tyr(Me)(8)bradykinin (Tyr(Me)(8)BK), was assessed. Tyr(Me)(8)BK produced a concentration- and endothelium-dependent relaxation that was decreased by about 30 - 40% after inhibition of nitric oxide (NO) synthase by N(G)-nitro-L-arginine (L-NOARG) or of cyclo-oxygenase by indomethacin; a greater decrease (about 40 - 50%) was observed after concomitant inhibition of the two pathways. High extracellular K(+) diminished Tyr(Me)(8)BK-induced relaxation by about 75% suggesting a major contribution of endothelium-derived hyperpolarization. The residual response was almost completely suppressed by NO synthase and cyclo-oxygenase inhibition. The K(+) channel inhibitors, tetrabutylammonium (non-specific) and charybdotoxin (specific for Ca(2+)-activated K(+) channel), suppressed Tyr(Me)(8)BK-induced relaxation resistant to L-NOARG and indomethacin. Inhibition of cytochrome P450 (clotrimazole or 7-ethoxyresorufin) decreased the NO/prostanoids-independent relaxation to Tyr(Me)(8)BK by more than 60%, while inhibition of the cannabinoid CB(1) receptor (SR 141716A) had only a moderate effect. Acetylcholine induced a concentration-dependent relaxation with characteristics nearly similar to the response to Tyr(Me)(8)BK. In contrast, the relaxation elicited by sodium nitroprusside was potentiated in the absence of NO (L-NOARG or removal of endothelium) but remained unchanged otherwise. These results indicate that the activation of kinin B(2) receptors in the rat isolated kidney elicits an endothelium-dependent vasorelaxation, mainly dependent on the activation of charybdotoxin-sensitive Ca(2+)-activated K(+) channels. In addition, cytochrome P450 derivatives appear to be involved.
- Published
- 2001
49. Role of bradykinin and eNOS in the anti-ischaemic effect of trandolapril
- Author
-
Cargnoni, Anna, Comini, Laura, Bernocchi, Palmira, Bachetti, Tiziana, Ceconi, Claudio, Curello, Salvatore, and Ferrari, Roberto
- Subjects
Male ,Indoles ,Nitric Oxide Synthase Type III ,Heart Ventricles ,Myocardial Ischemia ,Angiotensin-Converting Enzyme Inhibitors ,Myocardial Reperfusion Injury ,Angiotensin converting enzyme inhibitors ,anti-ischaemic eect ,bradykinin ,endothelial constitutive nitric oxide synthase ,trandolapril ,In Vitro Techniques ,Nitric Oxide ,NO ,Rats, Sprague-Dawley ,Ventricular Pressure ,Animals ,Aorta ,Dose-Response Relationship, Drug ,anti-ischaemic e ect ,Myocardium ,Rats ,Papers ,Nitric Oxide Synthase ,Energy Metabolism - Abstract
1. Angiotensin converting enzyme (ACE) inhibitors are under study in ischaemic heart diseases, their mechanism of action being still unknown. 2. The anti-ischaemic effect of trandolapril and the possible involvement of a bradykinin-modulation on endothelial constitutive nitric oxide synthase (eNOS) in exerting this effect, were investigated. 3. Three doses of trandolapril, chronically administered in vivo, were studied in isolated perfused rat hearts subjected to global ischaemia followed by reperfusion. 4. Trandolapril has an anti-ischaemic effect. The dose of 0.3 mg kg(-1) exerted the best effect reducing diastolic pressure increase during ischaemia (from 33.0+/-4.5 to 14.0+/-5.2 mmHg; P0.05 vs control) and reperfusion (from 86.1+/-9.4 to 22.2+/-4.1 mmHg; P0.01 vs control), improving functional recovery, counteracting creatine phosphokinase release and ameliorating energy metabolism after reperfusion. 5. Trandolapril down-regulated the baseline developed pressure. 6. Trandolapril increased myocardial bradykinin content (from 31.8+/-6.1 to 54.8+/-7.5 fmol/gww; P0.05, at baseline) and eNOS expression and activity in aortic endothelium (both P0.01 vs control) and in cardiac myocytes (from 11.3+/-1.5 to 17.0+/-2.0 mUOD microg protein(-1) and from 0.62+/-0.05 to 0.80+/-0.06 pmol mg prot(-1) min(-1); both P0.05 vs control). 7. HOE 140 (a bradykinin B(2) receptor antagonist) and NOS inhibitors counteracted the above-reported effects. 8. There was a negative correlation between myocyte's eNOS up-regulation and myocardial contraction down-regulation. 9. Our findings suggest that the down-regulation exerted by trandolapril on baseline cardiac contractility, through a bradykinin-mediated increase in NO production, plays a crucial role in the anti-ischaemic effect of trandolapril by reducing energy breakdown during ischaemia.
- Published
- 2001
50. Bradykinin regulation of salt transport across mouse inner medullary collecting duct epithelium involves activation of a Ca2+-dependent Cl− conductance
- Author
-
Kose, H, Boese, S H, Glanville, M, Gray, M A, Brown, C D A, and Simmons, N L
- Subjects
DNA, Complementary ,Patch-Clamp Techniques ,Time Factors ,Transcription, Genetic ,Molecular Sequence Data ,Gene Expression ,Kinins ,Bradykinin ,Cell Line ,Membrane Potentials ,Electrolytes ,Mice ,Chlorides ,Chloride Channels ,Sequence Homology, Nucleic Acid ,Animals ,RNA, Messenger ,Kidney Tubules, Collecting ,Kidney Medulla ,Ion Transport ,Base Sequence ,Epithelial Cells ,Sequence Analysis, DNA ,Papers ,Calcium ,Sequence Alignment - Abstract
The mechanism by which bradykinin regulates renal epithelial salt transport has been investigated using a mouse inner medullary renal collecting duct cell-line mIMCD-K2. Using fura-2 loaded mIMCD-K2 cells bradykinin (100 nM) has been shown to induce a transient increase in intracellular Ca(2+) via activation of bradykinin B2 receptors localized to both the apical and basolateral epithelial cell surfaces. In mIMCD-K2 epithelial cell-layers clamped in Ussing chambers, 100 nM bradykinin via apical and basolateral bradykinin B2 receptors stimulated a transient increase in inward short-circuit current (I:(sc)) of similar duration to the increase in intracellular Ca(2+). Replacements of the bathing solution Na(+) by the impermeant cation, N-methyl-D-glucamine and of Cl(-) and HCO(3)(-) by the impermeant anion gluconate at either the apical (no reduction) or basal bathing solutions (abolition of the response) are consistent with the bradykinin-stimulated increase in inward I:(sc) resulting from basal to apical Cl(-) (anion) secretion. Using the slow whole cell configuration of the patch-clamp technique, bradykinin was shown to activate a transient Cl(-) selective whole cell current which showed time-dependent activation at positive membrane potentials and time-dependent inactivation at negative membrane potentials. These currents were distinct from those activated by forskolin (CFTR), but identical to those activated by exogenous ATP and are therefore consistent with bradykinin activation of a Ca(2+)-dependent Cl(-) conductance. The molecular identity of the Ca(2+)-dependent Cl(-) conductance has been investigated by an RT - PCR approach. Expression of an mRNA transcript with 96% identity to mCLCA1/2 was confirmed, however an additional but distinct mRNA transcript with only 81% of the identity to mCLCA1/2 was identified.
- Published
- 2000
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