22 results on '"Orie, N. N."'
Search Results
2. Ca2+/calcineurin regulation of cloned vascular KATP channels: crosstalk with the protein kinase A pathway
- Author
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Orie, N N, Thomas, A M, Perrino, B A, Tinker, A, and Clapp, L H
- Published
- 2009
- Full Text
- View/download PDF
3. Enhanced expression of vascular KATP channels in an in vitro model of sepsis: C019
- Author
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Chan, Y L, Orie, N N, Singer, M, and Clapp, L H
- Published
- 2008
4. Enhanced sensitivity to salt-induced high blood pressure in diabetes mellitus
- Author
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Orie, N. N., Aloamaka, C. P., and Iyawe, V. I.
- Published
- 1994
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5. DIABETIC RAT AORTA RESPONSIVENESS TO D600 AND NIFEDIPINE
- Author
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Orie, N. N., primary and Aloamaka, C. P., additional
- Published
- 1993
- Full Text
- View/download PDF
6. Ca2+/calcineurin regulation of cloned vascular K ATP channels: crosstalk with the protein kinase A pathway.
- Author
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Orie, N. N., Thomas, A. M., Perrino, B. A., Tinker, A., and Clapp, L. H.
- Subjects
- *
PROTEIN kinases , *PHARMACOLOGY , *HYPOGLYCEMIC agents , *CHEMICAL reactions , *CARDIOVASCULAR agents , *VASODILATION , *SMOOTH muscle physiology , *BIOLOGICAL models , *BIOLOGICAL transport , *CALCIUM , *CELL lines , *COMPARATIVE studies , *CYTOLOGICAL techniques , *GENETIC techniques , *HYDROLASES , *IMMUNOSUPPRESSIVE agents , *ISOENZYMES , *RESEARCH methodology , *MEDICAL cooperation , *PHOSPHORYLATION , *POTASSIUM , *RESEARCH , *RESEARCH funding , *SMOOTH muscle , *TRANSFERASES , *EVALUATION research , *POTASSIUM antagonists , *CHEMICAL inhibitors , *PHARMACODYNAMICS , *PHYSIOLOGY - Abstract
Background and purpose: Vascular ATP-sensitive potassium (KATP) channels are activated by cyclic AMP elevating vasodilators through protein kinase A (PKA). Direct channel phosphorylation is a critical mechanism, though the phosphatase opposing these effects is unknown. Previously, we reported that calcineurin, a Ca2+-dependent phosphatase, inhibits KATP channels, though neither the site nor the calcineurin isoform involved is established. Given that the type-2 regulatory (RII) subunit of PKA is a substrate for calcineurin we considered whether calcineurin regulates channel activity through interacting with PKA. Experimental approach: Whole-cell recordings were made in HEK-293 cells stably expressing the vascular KATP channel (KIR6.1/SUR2B). The effect of intracellular Ca2+ and modulators of the calcineurin and PKA pathway on glibenclamide-sensitive currents were examined. Key results: Constitutively active calcineurin Aα but not Aβ significantly attenuated KATP currents activated by low intracellular Ca2+, whereas calcineurin inhibitors had the opposite effect. PKA inhibitors reduced basal KATP currents and responses to calcineurin inhibitors, consistent with the notion that some calcineurin action involves inhibition of PKA. However, raising intracellular Ca2+ (equivalent to increasing calcineurin activity), almost completely inhibited KATP channel activation induced by the catalytic subunit of PKA, whose enzymatic activity is independent of the RII subunit. In vitro phosphorylation experiments showed calcineurin could directly dephosphorylate a site in Kir6.1 that was previously phosphorylated by PKA. Conclusions and implications: Calcineurin Aα regulates KIR6.1/SUR2B by inhibiting PKA-dependent phosphorylation of the channel as well as PKA itself. Such a mechanism is likely to directly oppose the action of vasodilators on the KATP channel. British Journal of Pharmacology (2009) 157, 554–564; doi:10.1111/j.1476-5381.2009.00221.x; published online 7 May 2009 This article is commented on by Tammaro, pp. 551–553 of this issue and is part of a themed section on Endothelium in Pharmacology. For a list of all articles in this section see the end of this paper, or visit: [ABSTRACT FROM AUTHOR]
- Published
- 2009
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7. Increased intracellular generation of reactive oxygen species in mononuclear leukocytes from patients with diabetes mellitus type 2.
- Author
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Orie, N. N., Zidek, W., and Tepel, M.
- Published
- 2000
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8. Duration-dependent attenuation of acetylcholine-but not histamine-induced relaxation of the aorta in diabetes mellitus
- Author
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Orie, N. N., Aloamaka, C. P., and Iyawe, V. I.
- Published
- 1993
- Full Text
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9. Duration-dependent variability in the responses of diabetic rat aorta to noradrenaline and 5-hydroxytryptamine
- Author
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Orie, N. N. and Aloamaka, C. P.
- Published
- 1993
- Full Text
- View/download PDF
10. Increased intracellular reactive oxygen species in patients with end-stage renal failure: effect of hemodialysis.
- Author
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Tepel, Martin, Echelmeyer, Martin, Orie, Nelson N., Zidek, Walter, Tepel, M, Echelmeyer, M, Orie, N N, and Zidek, W
- Subjects
- *
HEMODIALYSIS , *KIDNEY diseases - Abstract
Background: Reactive oxygen species (ROS) have been implicated in various forms of cellular injury. ROS may cause cell damage and are involved in the pathophysiology of several diseases, including atherosclerosis and chronic inflammation.Methods: Disturbances of intracellular ROS levels were investigated in 28 patients with end-stage renal failure. The intracellular ROS levels were measured in lymphocytes before and after hemodialysis using biocompatible membranes and were compared with those from 11 patients with end-stage renal failure, not yet on renal replacement therapy, and 27 healthy control subjects. ROS levels were measured spectrophotometrically using the intracellular dye dichlorofluorescin diacetate.Results: The spontaneous production of ROS was significantly higher in lymphocytes from patients with end-stage renal failure compared with healthy control subjects (P < 0.01). The addition of 100 nmol/L phorbol-myristate-acetate (PMA) produced a significant increase of ROS, both in lymphocytes from patients with end-stage renal failure and healthy control subjects. The PMA-induced ROS increase was significantly higher in lymphocytes from patients with end-stage renal failure compared with healthy control subjects (P < 0.01). In patients with end-stage renal failure, not yet on renal replacement therapy, the PMA-induced ROS was also significantly higher compared with healthy control subjects. The PMA-induced ROS increases were significantly inhibited by catalase, but not by superoxide dismutase or the superoxide dismutase mimetic, tempol. PMA-induced ROS was significantly reduced by tyrphostin A51 in lymphocytes from patients with end-stage renal failure and from healthy control subjects (each P < 0.01), indicating the involvement of a tyrosine kinase-dependent pathway. In patients with end-stage renal failure, the spontaneous and the PMA-induced production of ROS was not significantly different before and after hemodialysis.Conclusions: Regular hemodialysis sessions using biocompatible membranes have no effect on the elevated intracellular ROS in patients with end-stage renal failure. [ABSTRACT FROM AUTHOR]- Published
- 2000
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11. Differential actions of the prostacyclin analogues treprostinil and iloprost and the selexipag metabolite, MRE-269 (ACT-333679) in rat small pulmonary arteries and veins.
- Author
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Orie NN, Ledwozyw A, Williams DJ, Whittle BJ, and Clapp LH
- Subjects
- Animals, Benzofurans pharmacology, Benzyl Compounds pharmacology, Epoprostenol pharmacology, Female, Imidazoles pharmacology, Male, Propionates pharmacology, Pulmonary Artery physiology, Pulmonary Veins physiology, Rats, Rats, Sprague-Dawley, Receptors, Epoprostenol antagonists & inhibitors, Vasodilation drug effects, Acetamides metabolism, Acetates metabolism, Acetates pharmacology, Epoprostenol analogs & derivatives, Iloprost pharmacology, Pulmonary Artery drug effects, Pulmonary Veins drug effects, Pyrazines metabolism, Pyrazines pharmacology
- Abstract
The prostacyclin (IP) receptor agonists, treprostinil, iloprost and the selexipag metabolite, MRE-269 (ACT-333679) were evaluated in rat distal pulmonary blood vessels. Small pulmonary arteries and veins were pre-contracted with the thromboxane mimetic, U46619 (25 and 100nM, respectively), and relaxation determined with and without IP receptor antagonists, RO1138452 and RO3244794. In arteries, treprostinil was a more potent vasorelaxant than iloprost, while the efficacy of iloprost was greater. In pulmonary arteries, treprostinil-induced relaxation was essentially abolished by both IP antagonists (1μM), while responses to iloprost were partially inhibited. Both treprostinil and iloprost were equipotent, prominently relaxing pulmonary veins with responses being similarly and partially sensitive to IP antagonists. In contrast, RO1138452 failed to inhibit relaxations to MRE-269 in either pulmonary arteries or veins, suggesting no involvement of typical IP receptors. Thus, rat pulmonary tissues cannot be considered appropriate to assess classical IP receptors using the proposed highly selective non-prostanoid agonist MRE-269, contrasting with the IP receptor agonism profile of prostacyclin analogues, iloprost and treprostinil., (Copyright © 2013 Elsevier Inc. All rights reserved.)
- Published
- 2013
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12. Reactive oxygen species in essential hypertension and non-insulin-dependent diabetes mellitus.
- Author
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Orie NN, Zidek W, and Tepel M
- Subjects
- Biomarkers blood, Blood Pressure, Calcium metabolism, Cytosol metabolism, Enzyme Inhibitors pharmacology, Fluorescent Dyes, Fura-2 metabolism, Humans, Intracellular Fluid metabolism, Lymphocyte Activation drug effects, Lymphocytes drug effects, Middle Aged, N-Formylmethionine Leucyl-Phenylalanine pharmacology, Oxidative Stress, Protein Kinase C antagonists & inhibitors, Protein-Tyrosine Kinases antagonists & inhibitors, Rhodamines metabolism, Superoxide Dismutase pharmacology, Diabetes Mellitus, Type 2 blood, Hypertension blood, Lymphocytes metabolism, Reactive Oxygen Species metabolism
- Abstract
To evaluate whether increased levels of reactive oxygen species (ROS) are involved in the pathogenesis of essential hypertension (EH) and non-insulin-dependent diabetes mellitus (NIDDM), both resting and stimulated levels of intracellular ROS were measured in lymphocytes from patients with EH (n = 10), NIDDM (n = 16) and age-matched healthy individuals (control subjects, n = 19). ROS was monitored with the dye, dihydrorhodamine-123 (DHR; 1 micromol/L) in the presence or absence of superoxide dismutase (superoxide scavenger), sodium azide (singlet oxygen/hydrogen peroxide scavenger), genistein (tyrosine kinase inhibitor), or bisindolylmaleimide (protein kinase C inhibitor). Simultaneous monitoring of cytosolic [Ca2+]i was done with fura-2. Resting ROS levels were significantly higher in NIDDM (4.71+/-0.25 nmol/10(6) cells; mean +/- SEM, P<.05) compared with EH (4.03+/-0.22 nmol/10(6) cells) or controls (4.05+/-0.15 nmol/10(6) cells). The formyl-Met-Leu-Phenylalanine-(fMLP)-induced ROS generation was significantly higher in NIDDM (21.92+/-2.23 nmol/10(6) cells; P<.05) compared with EH (14.58+/-1.90 nmol/10(6) cells) or control (16.06+/-1.22 nmol/10(6) cells). The fMLP-induced ROS increase was significantly reduced in the presence of sodium azide in all groups (P<.01) but was largely unaffected in the presence of SOD. Genistein and bisindolylmaleimide significantly inhibited the fMLP-induced ROS in all groups. The fMLP-induced [Ca2+]i increase was significantly higher in NIDDM (71+/-12 nmol/L, P <.01) compared with EH (42+/-4 nmol/L) and control subjects (35+/-3 nmol/L). Phytohemagglutinin was more effective in increasing [Ca2+]i than ROS. It is concluded that ROS may play a role in the metabolic syndrome of NIDDM but not in EH.
- Published
- 1999
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13. Chemoattractant- and mitogen-induced generation of reactive oxygen species in human lymphocytes: the role of calcium.
- Author
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Orie NN, Zidek W, and Tepel M
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- Calcium administration & dosage, Calcium pharmacology, Calcium Signaling drug effects, Cytosol metabolism, Dose-Response Relationship, Drug, Humans, In Vitro Techniques, Ion Transport drug effects, Calcium metabolism, Lymphocytes drug effects, Lymphocytes metabolism, N-Formylmethionine Leucyl-Phenylalanine pharmacology, Phytohemagglutinins pharmacology, Reactive Oxygen Species metabolism
- Abstract
This study examined the role of calcium in the generation of reactive oxygen species (ROS) in human lymphocytes activated by the chemoattractant formyl-Met-Leu-Phe (fMLP) and the T-cell mitogen phytohaemagglutinin (PHA). The concentrations of cytosolic calcium ([Ca2+]i) and ROS were monitored simultaneously with a fluorescence spectrophotometer after the cells had been incubated in fura-2 (calcium-sensitive dye) and 2',7'-dichlorofluorescein diacetate (DCF-DA, ROS-sensitive dye). The lymphocytes were stimulated with fMLP (200 nmol l-1) or PHA (10 micromol l-1) in the absence and presence of extracellular calcium. A dose-response test was also conducted for extracellular calcium. fMLP and PHA significantly increased both [Ca2+]i (P < 0.001) and ROS concentrations (P < 0. 001) above the control levels in the presence of extracellular calcium. However, such increases were abolished in the absence of extracellular calcium, suggesting total dependence of the responses to both fMLP and PHA on transplasma-membrane calcium influx. There were also graded increases in ROS with increasing concentrations of extracellular calcium. The results show that transplasma-membrane calcium influx is essential for fMLP- and PHA-induced generation of reactive oxygen species in human lymphocytes.
- Published
- 1999
14. Nifedipine effectively lowers salt-induced high blood pressure in diabetic rats.
- Author
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Orie NN and Anyaegbu NO
- Subjects
- Animals, Blood Pressure drug effects, Diabetic Angiopathies chemically induced, Hypertension chemically induced, Male, Norepinephrine pharmacology, Rats, Rats, Wistar, Vasoconstrictor Agents pharmacology, Diabetic Angiopathies drug therapy, Hypertension drug therapy, Nifedipine therapeutic use, Vasodilator Agents therapeutic use
- Abstract
This study examined the antihypertensive efficacy of nifedipine (a calcium channel blocker) in salt-loaded alloxan-diabetic rats. Significant increases in basal mean arterial blood pressures were observed after six weeks of high salt (8% NaCl) feeding in both diabetic (p < 0.05) and nondiabetic (p < 0.05) rats. The values were 129.95+/-3.14 mmHg for control (C); 149.22+/-8.83 mmHg for nondiabetic salt-fed (N-SF) and 150.60+/-8.01 mmHg for diabetic salt-fed (D-SF) groups. The non-salt-fed diabetic group (D) had a pressure of 136.75+/-6.66 mmHg. The maximum mean arterial blood pressures in response to noradrenaline (10(-9)-10(-5) M) infusion were significantly (p < 0.05) higher in the N-SF and D-SF groups than in the control. Nifedipine (100 microg/Kg) reduced significantly the pressures (both before and following noradrenaline infusion) in the salt-fed groups (p < 0.001). The inhibitory effect of nifedipine was more marked (p < 0.01) in the diabetic salt-fed than in the nondiabetic salt-fed. It is therefore suggested that nifedipine is effective in lowering salt-induced high blood pressure in diabetic rats.
- Published
- 1999
- Full Text
- View/download PDF
15. Tyrosine and calcium/calmodulin kinases are common signaling components in the generation of reactive oxygen species in human lymphocytes.
- Author
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Orie NN, Zidek W, and Tepel M
- Subjects
- Aminoquinolines pharmacology, Calcium-Calmodulin-Dependent Protein Kinase Type 2, Calcium-Calmodulin-Dependent Protein Kinases antagonists & inhibitors, Catalase pharmacology, Cinnamates pharmacology, Dimethyl Sulfoxide pharmacology, Dose-Response Relationship, Drug, Enzyme Inhibitors pharmacology, Humans, Indoles pharmacology, Lymphocyte Activation drug effects, Lymphocytes drug effects, Maleimides pharmacology, N-Formylmethionine Leucyl-Phenylalanine pharmacology, Sodium Azide pharmacology, Sulfides pharmacology, Tetradecanoylphorbol Acetate pharmacology, Tyrphostins pharmacology, Calcium-Calmodulin-Dependent Protein Kinases metabolism, Lymphocytes metabolism, Protein-Tyrosine Kinases metabolism, Reactive Oxygen Species metabolism, Signal Transduction
- Abstract
This study examined the signaling mechanism involved in the generation of reactive oxygen species (ROS) in human lymphocytes activated by formyl-Met-Leu-Phenylalanine (fMLP; 200 nmol/L) or phorbol-myristate-acetate (PMA; 100 nmol/L). ROS were monitored spectrophotometrically using dichlorofluorescin diacetate. fMLP and PMA significantly increased ROS above the control levels (p<0.05 and 0.001, respectively). These increases were significantly inhibited by catalase, sodium azide, and dimethylsulfoxide but not by superoxide dismutase, suggesting that the ROS apparently included hydrogen peroxide, singlet oxygen and hydroxyl ion but not superoxide anion. PMA-induced responses were reduced by tyrphostin (p<0.01), ST-638 (p<0.05), KN-62 (p<0.001), bisindolylmaleimide (p<0.001), RO-31-8220 (p<0.001), and by LY-83583 (p<0.001), suggesting significant involvement of tyrosine kinase, calcium/calmodulin kinase II, protein kinase C and guanylyl cyclase. fMLP-induced responses were significantly reduced by only tyrphostin (p<0.001), ST-638 (p<0.05), and KN-62 (p<0.01). The results show that tyrosine kinase and calcium/calmodulin kinase II are common signalling components in the production of reactive oxygen species in activated lymphocytes.
- Published
- 1999
- Full Text
- View/download PDF
16. Comparison of normal respiratory function values in young Kenyans with those of other Africans and Caucasians.
- Author
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Orie NN
- Subjects
- Adult, Australia, Ethiopia, Female, Forced Expiratory Flow Rates physiology, Forced Expiratory Volume physiology, Humans, Kenya, Linear Models, Male, Peak Expiratory Flow Rate physiology, Reference Values, Respiratory Function Tests, South Africa, Vital Capacity physiology, White People, Black People, Lung physiology
- Abstract
Objective: To compare the normal respiratory function values in young Kenyans with those reported for regional African neighbours and Caucasians., Design: Forced expiratory volume in one second (FEV1), forced vital capacity (FVC) and peak expiratory flow rate (PEFR) were measured in a non-randomised sample of young indigenous Kenyans and the values were compared with those of age-matched regional African neighbours (Ethiopians and South Africans) and Caucasians (Australians)., Setting: Faculty of Health Sciences, Moi University, Eldoret., Subjects: Eighty eight apparently healthy young Kenyan university students (64 males, 20-25 years and 24 females, 19-23 years) were examined., Results: The mean values (males versus females) were FEV1, 3.95 +/- 0.07 versus 2.97 +/- 0.08, FVC, 4.31 +/- 0.08 versus 3.19 +/- 0.09, and PEFR, 586.30 +/- 8.54 versus 438.30 +/- 8.55. The values for females were 25-26% less than those for males. The expiratory ratios (FEV1/FVC x 100) were 92.22 +/- 0.60% and 93.44 +/- 0.61% for males and females respectively, well within normal range. The FEV1, FVC and PEFR for both males and females correlated positively with heights., Conclusion: These results were comparable to values reported for age-matched regional neighbours (Ethiopians and South Africans) but were lower than those reported for Australian caucasians. This highlights the need for the Kenyan population to have its own local reference values.
- Published
- 1999
17. Insulin therapy could prevent salt-induced high blood pressure in diabetes mellitus.
- Author
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Orie NN and Osirim FE
- Subjects
- Animals, Disease Models, Animal, Drug Evaluation, Preclinical, Humans, Random Allocation, Rats, Rats, Wistar, Diabetes Mellitus, Experimental complications, Diabetes Mellitus, Experimental drug therapy, Hypertension etiology, Hypertension prevention & control, Hypoglycemic Agents therapeutic use, Insulin therapeutic use, Sodium Chloride, Dietary adverse effects
- Abstract
The effectiveness of insulin replacement therapy in the prevention of salt-induced hypertension in diabetes mellitus was examined using Alloxan diabetic rats. Early daily (eight units/day) treatment with insulin prevented the development of high blood pressure after six weeks of high-salt feeding. The mean arterial pressure (MAP) for the early insulin-treated and salt-fed group (DET-SF) was 123.37 +/- 6.37 mmHg which was close to the value for normal (control) rats 128.17 +/- 4.84 mmHg, but significantly (p < 0.001) less than that of the untreated diabetic salt-fed group (DSF) which was 164.58 +/- 8.33 mmHg. The nondiabetic salt-fed (NDSF) group had MAP of 150.27 +/- 4.24 mmHg. Late commencement of insulin therapy did not significantly affect the sensitivity of the diabetic rats to high-salt diet. The results suggest that early commencement of insulin therapy could prevent the development of high blood pressure in diabetic rats.
- Published
- 1997
18. Direct vascular effects of plantain extract in rats.
- Author
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Orie NN
- Subjects
- Animals, Male, Norepinephrine pharmacology, Portal Vein physiology, Rats, Rats, Wistar, Serotonin pharmacology, Vasoconstriction drug effects, Vasoconstrictor Agents pharmacology, Vasodilation, Aorta drug effects, Plant Extracts pharmacology, Portal Vein drug effects
- Abstract
Responses of the aorta and portal veins isolated from rats to aqueous extract of plantain (Musa paradisiaca) were studied. The extract produced concentration-dependent relaxation in both noradrenaline- and KCl-contracted aortic rings. The maximum relaxation in noradrenaline-contracted rings was 52.49 +/- 6.63% and in KCl-contracted rings was 77.51 +/- 2.52% of the initial tensions developed in response to the contractile agents. The extract also produced significant (P < 0.01) inhibition of the maximum aortic contractile response to noradrenaline and completely abolished the spontaneous contractions of the portal veins. Serotonin (5-hydroxytryptamine), unlike the extract, produced contraction rather than relaxation of the aortic rings. The results show a non-specific relaxing and inhibiting effect of plantain extract on aortic and portal smooth muscles, an effect that is not attributable to its abundant serotonin content.
- Published
- 1997
- Full Text
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19. Altered responses of isolated aortic smooth muscle following chronic ingestion of palm oil diets in rats.
- Author
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Owu DU, Orie NN, and Osim EE
- Subjects
- Acetylcholine pharmacology, Animals, Dietary Fats, Unsaturated administration & dosage, Dose-Response Relationship, Drug, Endothelium, Vascular drug effects, Fats, Unsaturated chemistry, Hot Temperature, Male, Norepinephrine pharmacology, Oxidation-Reduction, Palm Oil, Plant Oils administration & dosage, Plant Oils chemistry, Potassium Chloride pharmacology, Rats, Rats, Wistar, Aorta, Thoracic drug effects, Dietary Fats, Unsaturated pharmacology, Muscle, Smooth, Vascular drug effects, Plant Oils pharmacology, Vasoconstrictor Agents pharmacology, Vasodilator Agents pharmacology
- Abstract
The responsiveness of the rat aorta after chronic consumption of 15% (wt/wt) fresh and thermally oxidized palm oil diets was studied under standard organ bath procedures. Aortic rings from the oxidized oil-fed group showed significantly (P < 0.05) enhanced vascular responses to noradrenaline and potassium chloride when compared with the control and fresh palm oil-fed groups. The maximum tensions were 285.10 +/- 30 mg/mg tissue weight for the oxidized oil-fed group and 148.98 +/- 36 mg/mg for the control in response to noradrenaline. The fresh oil-fed group produced maximum tension of 133.9 +/- 20 mg/mg which was not significantly different from the control. The trend was similar with potassium chloride. The maximum tensions were 206.31 +/- 25 mg/mg for the oxidized oil-fed group and 93.33 +/- 13 mg/mg for the control group. The fresh oil-fed group produced maximum tension of 109.31 +/- 7.8 mg/mg which was not significantly different from the control. Relaxation to acetylcholine was significantly (P < 0.01) attenuated in the aortic rings obtained from the oxidized palm oil-fed group when compared with the control and fresh palm oil-fed groups. The percentage maximum relaxations to acetylcholine were 28.1 +/- 6.7% in the oxidized oil-fed group, 71.4 +/- 6.0% in control and 78.2 +/- 6.0% in the fresh oil-fed groups. The relaxation in the fresh oil-fed group was not significantly different from control. These results suggest that functional changes occur in rat blood vessels after chronic consumption of thermally oxidized palm oil.
- Published
- 1997
20. Enhanced Na-K ATPase activity in the aorta may explain the unaltered contractile responses to KCl in diabetes mellitus.
- Author
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Orie NN, Aloamaka CP, and Antai AB
- Subjects
- Animals, Aorta drug effects, Aorta enzymology, Calcium metabolism, Calcium Chloride pharmacology, In Vitro Techniques, Male, Muscle Contraction drug effects, Muscle Relaxation drug effects, Muscle, Smooth, Vascular drug effects, Rats, Rats, Wistar, Diabetes Mellitus, Experimental physiopathology, Muscle, Smooth, Vascular enzymology, Potassium Chloride pharmacology, Sodium-Potassium-Exchanging ATPase metabolism
- Abstract
Sodium-potassium ATPase activity and transmembrane calcium influx in the aortic smooth muscle from control and diabetic rats were assessed indirectly through the measurement of KCl relaxation and contractile responses to CaCl2 in attempts to explain the contractile responses to KCl following streptozotocin-induced diabetes mellitus. There were no significant changes in the maximum contractile responses of the aortas from 4 and 12 week diabetic rats to KCl even when significant increases in calcium influx were demonstratable. On the other hand, the diabetic aortas were significantly (P < 0.05) more sensitive to KCl-induced relaxations than the controls. This provides an indirect evidence for increased activity of the sodium-postassium ATPase enzyme in the aortas from streptozotocin diabetic rats. This may, atleast in part, explain the inability of KCl to produce greater than normal contractions of the aortas from diabetic rats.
- Published
- 1993
21. The bronchodilator effect of Garcinia Kola.
- Author
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Orie NN and Ekon EU
- Subjects
- Adolescent, Adult, Airway Resistance, Drug Evaluation, Humans, Male, Nigeria, Time Factors, Forced Expiratory Volume, Medicine, African Traditional, Peak Expiratory Flow Rate, Plants, Medicinal physiology, Seeds physiology, Vital Capacity
- Abstract
This work investigated the bronchodilator effect of Garcinia Kola (Bitter Kola) in normal Nigerians. Nineteen undergraduate male students (17-25 years) were used for the study which involved the consumption of Garcinia Kola (15 grammes per subject) and the measurement of peak expiratory flow rate (PEFR), forced expiratory volume in one second (FEV1) and forced vital capacity (FVC) at intervals of 30 minutes up to a maximum of 90 minutes. Each subject served as his own control. There was time-dependent increases in the measured parameters. However, only the PEFR showed significant (p < 0.05) increase and this was observed at the 60th minute. This probably shows a mild bronchodilator effect of this Kola.
- Published
- 1993
22. The effect of nocotiana tabacum (snuff) on blood pressure and pulse rate of Nigerians.
- Author
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Orie NN and Ibanga IN
- Subjects
- Adult, Aged, Carbonates administration & dosage, Dose-Response Relationship, Drug, Humans, Male, Middle Aged, Blood Pressure drug effects, Carbonates adverse effects, Heart Rate drug effects, Plants, Toxic, Tobacco, Smokeless adverse effects
- Abstract
Nutritional and environmental factors are now known to affect the blood pressure and pulse rate of man. The present study investigated the effect of nicotiana tabacum on these parameters. Thirty-three male Nigerians (20-68 years) living in Calabar, Nigeria were used for this study. The subjects were treated at three different periods with snuff containing varied concentrations of Natron (0.5g and 10g/100g of snuff) and their systolic and diastolic pressures as well as pulse rate were measured at intervals of 30 minutes up to a maximum of 90 minutes. Each subject served as his own control. There were significant and time-dependent increases in the parameters measured. In addition, the increases were more marked in the absence of Natron than in its presence.
- Published
- 1992
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