59 results on '"Claude Rouch"'
Search Results
2. Disruption of Pituitary Gonadotrope Activity in Male Rats After Short- or Long-Term High-Fat Diets Is Not Associated With Pituitary Inflammation
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Ghislaine Garrel, Claude Rouch, David L’Hôte, Salma Tazi, Nadim Kassis, Frank Giton, Julien Dairou, Pascal Dournaud, Pierre Gressens, Christophe Magnan, Céline Cruciani-Guglielmacci, and Joëlle Cohen-Tannoudji
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Inflammation ,Male ,Overnutrition ,Endocrinology, Diabetes and Metabolism ,Pituitary Diseases ,Pituitary Gland ,Animals ,Diet, High-Fat ,Dietary Fats ,Rats - Abstract
Overnutrition is associated with the activation of inflammatory pathways in metabolically linked organs and an early hypothalamic inflammation is now known to disrupt the central control of metabolic function. Because we demonstrated that fatty acids (FA) target the pituitary and affect gonadotropin synthesis, we asked whether overnutrition induces pituitary inflammation that may contribute to obesity-associated disorders in the control of reproduction. We analyzed pituitary inflammation and hypothalamic-pituitary-testicular axis in male rats fed a short- (4 weeks) or long-term (20 weeks) high-fat diet. The effect of diet enrichment with the ω3 polyunsaturated FA, DHA, was also analyzed. After only 4 weeks and before weight gain of rats, high-fat diet caused a significant decrease in pituitary gonadotropin and hypothalamic GnRH transcript levels despite unchanged testosterone and inhibin B levels. Contrasting with the hypothalamus, there was no concomitant increases in gene expression of pituitary inflammatory mediators and even a reduction of prototypical cytokines such as interleukin-1β and TNF-α. No inflammation was still detected in the pituitary after 20 weeks although gonadotropin transcripts and circulating levels were still altered. Gonadotropins were the only pituitary hormones remaining affected at this stage of the regimen, underlying a differential susceptibility of pituitary lineages to metabolic disorders. DHA enrichment of the diet did not prevent alterations of gonadotrope activity due to either a long- or a short-term high-fat diet although it blocked early hypothalamic inflammation and attenuated several metabolic effects. Taken together, our findings suggest that high-fat diet-induced defects in gonadotrope activity in male rats occurred despite a lack of pituitary inflammation.
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- 2022
3. Dominant gut Prevotella copri in gastrectomised non-obese diabetic Goto–Kakizaki rats improves glucose homeostasis through enhanced FXR signalling
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Jessica Wasserscheid, Marc-Emmanuel Dumas, Antonis Myridakis, Lyamine Hedjazi, Francois Brial, Noémie Péan, Dominique Gauguier, Ken Dewar, Mylène Vincent, Christophe Magnan, Aurélie Le Lay, Mark Lathrop, Elin Grundberg, Claude Rouch, Centre de Recherche des Cordeliers (CRC), Université Pierre et Marie Curie - Paris 6 (UPMC)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM), Toxicité environnementale, cibles thérapeutiques, signalisation cellulaire (T3S - UMR_S 1124), Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Institut National de la Santé et de la Recherche Médicale (INSERM), McGill University and Genome Quebec Innovation Centre, Unité de Biologie Fonctionnelle et Adaptative (BFA (UMR_8251 / U1133)), Université Paris Diderot - Paris 7 (UPD7)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Imperial College London, Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Université Paris Diderot - Paris 7 (UPD7)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM), Centre de Recherche des Cordeliers (CRC (UMR_S_1138 / U1138)), École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU), McGill University = Université McGill [Montréal, Canada], Université Paris Descartes - Paris 5 (UPD5)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM), Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Université de Strasbourg (UNISTRA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), and Commission of the European Communities
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0301 basic medicine ,Blood Glucose ,Male ,IMPACT ,Endocrinology, Diabetes and Metabolism ,[SDV]Life Sciences [q-bio] ,Prevotella ,Y GASTRIC BYPASS ,Type 2 diabetes ,Gut flora ,chemistry.chemical_compound ,0302 clinical medicine ,Glucose homeostasis ,ComputingMilieux_MISCELLANEOUS ,Glycogen ,Goto-Kakizaki rat ,MICROBIOTA ,3. Good health ,TARGET ,Goto–Kakizaki rat ,Life Sciences & Biomedicine ,Signal Transduction ,medicine.medical_specialty ,030209 endocrinology & metabolism ,METABOLISM ,Biology ,Cholesterol 7 alpha-hydroxylase ,digestive system ,Article ,DIET ,1117 Public Health and Health Services ,Endocrinology & Metabolism ,03 medical and health sciences ,Internal medicine ,16S rDNA ,Internal Medicine ,medicine ,Animals ,[CHIM]Chemical Sciences ,Microbiome ,Carbohydrate-responsive element-binding protein ,BARIATRIC SURGERY ,Science & Technology ,Body Weight ,1103 Clinical Sciences ,medicine.disease ,biology.organism_classification ,Bile acids ,Gastrointestinal Microbiome ,Rats ,030104 developmental biology ,Endocrinology ,DUODENAL-JEJUNAL BYPASS ,chemistry ,Diabetes Mellitus, Type 2 ,1114 Paediatrics and Reproductive Medicine ,IMMUNE-SYSTEM ,Farnesoid X receptor ,WEIGHT - Abstract
Aims/hypothesis Drug and surgical-based therapies in type 2 diabetes are associated with altered gut microbiota architecture. Here we investigated the role of the gut microbiome in improved glucose homeostasis following bariatric surgery. Methods We carried out gut microbiome analyses in gastrectomised (by vertical sleeve gastrectomy [VSG]) rats of the Goto–Kakizaki (GK) non-obese model of spontaneously occurring type 2 diabetes, followed by physiological studies in the GK rat. Results VSG in the GK rat led to permanent improvement of glucose tolerance associated with minor changes in the gut microbiome, mostly characterised by significant enrichment of caecal Prevotella copri. Gut microbiota enrichment with P. copri in GK rats through permissive antibiotic treatment, inoculation of gut microbiota isolated from gastrectomised GK rats, and direct inoculation of P. copri, resulted in significant improvement of glucose tolerance, independent of changes in body weight. Plasma bile acids were increased in GK rats following inoculation with P. copri and P. copri-enriched microbiota from VSG-treated rats; the inoculated GK rats then showed increased liver glycogen and upregulated expression of Fxr (also known as Nr1h4), Srebf1c, Chrebp (also known as Mlxipl) and Il10 and downregulated expression of Cyp7a1. Conclusions Our data underline the impact of intestinal P. copri on improved glucose homeostasis through enhanced bile acid metabolism and farnesoid X receptor (FXR) signalling, which may represent a promising opportunity for novel type 2 diabetes therapeutics.
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- 2020
4. Protective role of the ELOVL2/docosahexaenoic acid axis in glucolipotoxicity-induced apoptosis in rodent beta cells and human islets
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Hervé Le Stunff, Kelly Meneyrol, Nadim Kassis, Mark Ibberson, Julien Véret, Christophe Magnan, Lara Bellini, Isabelle Hainault, Jessica Denom, Céline Cruciani-Guglielmacci, Véronique Lenoir, Piero Marchetti, Agnieszka Blachnio-Zabielska, Mélanie Campana, Marta Chacinska, Carina Prip-Buus, Marco Bugliani, Bernard Thorens, Claude Rouch, Unité de Biologie Fonctionnelle et Adaptative (BFA (UMR_8251 / U1133)), Université Paris Diderot - Paris 7 (UPD7)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Department of Clinical and Experimental Medicine [Pisa, Italy], University of Pisa [Italy], Centre de Recherche des Cordeliers (CRC), Université Paris Diderot - Paris 7 (UPD7)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM), Institut Cochin (IC UM3 (UMR 8104 / U1016)), Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), FACULTAD DE CIENCIAS Y FILOSOFIA, Swiss Institute of Bioinformatics [Lausanne] (SIB), Université de Lausanne (UNIL), Medical University of Bialystok, Université Paris Diderot, Sorbonne Paris Cité, Paris, France, Université Paris Diderot - Paris 7 (UPD7), Laboratoire de physiopathologie de la nutrition (LPN), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7), Université Paris Diderot - Paris 7 (UPD7)-École pratique des hautes études (EPHE)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM), SIB Swiss Institute of Bioinformatics, and Université de Lausanne
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AMPK ,0301 basic medicine ,medicine.medical_specialty ,Ceramide ,Docosahexaenoic Acids ,Fatty Acid Elongases ,Endocrinology, Diabetes and Metabolism ,[SDV]Life Sciences [q-bio] ,Palmitates ,Apoptosis ,030209 endocrinology & metabolism ,Pancreatic beta cells ,Islets of Langerhans ,Mice ,03 medical and health sciences ,chemistry.chemical_compound ,Endocrinology ,0302 clinical medicine ,Carnitine palmitoyltransferase 1 ,Downregulation and upregulation ,ELOVL2 ,Acetyltransferases ,Insulin-Secreting Cells ,Internal medicine ,Internal Medicine ,medicine ,Animals ,Glucose homeostasis ,ComputingMilieux_MISCELLANEOUS ,chemistry.chemical_classification ,food and beverages ,Fatty acid ,Type 2 diabetes ,DHA ,Glucolipotoxicity ,Diabetes and Metabolism ,Mitochondrial β-oxidation ,Glucose ,030104 developmental biology ,chemistry ,Docosahexaenoic acid ,Beta cell ,Oxidation-Reduction ,Etomoxir - Abstract
Dietary n-3 polyunsaturated fatty acids, especially docosahexaenoic acid (DHA), are known to influence glucose homeostasis. We recently showed that Elovl2 expression in beta cells, which regulates synthesis of endogenous DHA, was associated with glucose tolerance and played a key role in insulin secretion. The present study aimed to examine the role of the very long chain fatty acid elongase 2 (ELOVL2)/DHA axis on the adverse effects of palmitate with high glucose, a condition defined as glucolipotoxicity, on beta cells. We detected ELOVL2 in INS-1 beta cells and mouse and human islets using quantitative PCR and western blotting. Downregulation and adenoviral overexpression of Elovl2 was carried out in beta cells. Ceramide and diacylglycerol levels were determined by radio-enzymatic assay and lipidomics. Apoptosis was quantified using caspase-3 assays and poly (ADP-ribose) polymerase cleavage. Palmitate oxidation and esterification were determined by [U-14C]palmitate labelling. We found that glucolipotoxicity decreased ELOVL2 content in rodent and human beta cells. Downregulation of ELOVL2 drastically potentiated beta cell apoptosis induced by glucolipotoxicity, whereas adenoviral Elovl2 overexpression and supplementation with DHA partially inhibited glucolipotoxicity-induced cell death in rodent and human beta cells. Inhibition of beta cell apoptosis by the ELOVL2/DHA axis was associated with a decrease in ceramide accumulation. However, the ELOVL2/DHA axis was unable to directly alter ceramide synthesis or metabolism. By contrast, DHA increased palmitate oxidation but did not affect its esterification. Pharmacological inhibition of AMP-activated protein kinase and etomoxir, an inhibitor of carnitine palmitoyltransferase 1 (CPT1), the rate-limiting enzyme in fatty acid β-oxidation, attenuated the protective effect of the ELOVL2/DHA axis during glucolipotoxicity. Downregulation of CPT1 also counteracted the anti-apoptotic action of the ELOVL2/DHA axis. By contrast, a mutated active form of Cpt1 inhibited glucolipotoxicity-induced beta cell apoptosis when ELOVL2 was downregulated. Our results identify ELOVL2 as a critical pro-survival enzyme for preventing beta cell death and dysfunction induced by glucolipotoxicity, notably by favouring palmitate oxidation in mitochondria through a CPT1-dependent mechanism.
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- 2018
5. Alterations in the Serotonin and Dopamine Pathways by Cystathionine Beta Synthase Overexpression in Murine Brain
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Fabrice Daubigney, Jacqueline London, F K Ndiaye, Julien Dairou, Nathalie Janel, Linh-Chi Bui, Benoit Souchet, Christophe Magnan, Claude Rouch, Serge Luquet, Unité de Biologie Fonctionnelle et Adaptative (BFA (UMR_8251 / U1133)), and Université Paris Diderot - Paris 7 (UPD7)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)
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0301 basic medicine ,Male ,medicine.medical_specialty ,Serotonin ,[SDV]Life Sciences [q-bio] ,Dopamine ,Neuroscience (miscellaneous) ,Cystathionine beta-Synthase ,Mice, Transgenic ,Transsulfuration pathway ,Statistics, Nonparametric ,03 medical and health sciences ,Cellular and Molecular Neuroscience ,chemistry.chemical_compound ,0302 clinical medicine ,Internal medicine ,medicine ,Animals ,Neurotransmitter ,ComputingMilieux_MISCELLANEOUS ,biology ,Brain ,medicine.disease ,Cystathionine beta synthase ,Serotonin pathway ,Mice, Inbred C57BL ,030104 developmental biology ,Monoamine neurotransmitter ,Endocrinology ,Neurology ,chemistry ,biology.protein ,Female ,Trisomy ,Chromosome 21 ,030217 neurology & neurosurgery ,medicine.drug - Abstract
Cystathionine beta synthase (CBS) is one of the 225 genes on chromosome 21 (HSA 21) that are triplicated in persons with trisomy 21 (Down syndrome). Although most triplicate HSA21 genes have their orthologous genes on murine chromosome 16, the murine ortholog of hCBS is on murine chromosome 17 and thus is not present in the well-studied Ts65Dn mouse model of trisomy 21. Persons with trisomy 21 (T21) present deficits in neurotransmission and exhibit early brain aging that can partially be explained by monoamine neurotransmitter alterations. We used transgenic mice for the hCBS gene, which overexpress the CBS protein in various brain regions, to study if CBS overexpression induces modifications in the monoamine neurotransmitters in the hypothalamus, thalamus, hippocampus, and striatum from transgenic and control female and male mice aged 3–4 months and 11–12 months. Sex, age, and brain area each influenced neurotransmitter levels. Briefly, the serotonin pathway was modified by CBS overexpression in various brain areas in female mice but not in male mice. The dopamine pathway was modified in brain regions according to sex and age. These results may allow us to better understand the role of the transsulfuration pathway and especially CBS overexpression in the metabolism of biogenic amines and the catecholamine catabolism in persons with trisomy 21.
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- 2018
6. Overexpression of the DYRK1A Gene (Dual-Specificity Tyrosine Phosphorylation-Regulated Kinase 1A) Induces Alterations of the Serotoninergic and Dopaminergic Processing in Murine Brain Tissues
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Julien Dairou, Jacqueline London, Benoit Souchet, Linh Chi Bui, Fabrice Daubigney, Christophe Magnan, Nathalie Janel, Serge Luquet, Jean-Maurice Delabar, Hind Medjaoui, Elodie Assayag, Claude Rouch, Unité de Biologie Fonctionnelle et Adaptative (BFA (UMR_8251 / U1133)), Université Paris Diderot - Paris 7 (UPD7)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), and Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)
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Male ,0301 basic medicine ,EXPRESSION ,Serotonin ,medicine.medical_specialty ,SEX-DIFFERENCES ,DYRK1A ,Dopamine ,[SDV]Life Sciences [q-bio] ,Neuroscience (miscellaneous) ,Protein Serine-Threonine Kinases ,Biology ,EARLY PHARMACOTHERAPY ,METABOLISM ,Serotonergic ,COGNITIVE PERFORMANCE ,03 medical and health sciences ,Cellular and Molecular Neuroscience ,chemistry.chemical_compound ,0302 clinical medicine ,Internal medicine ,medicine ,Animals ,DOWN-SYNDROME ,Phosphorylation ,Dopaminergic ,Brain ,Tyrosine phosphorylation ,Protein-Tyrosine Kinases ,3. Good health ,ALZHEIMERS-DISEASE ,Disease Models, Animal ,MICE ,030104 developmental biology ,Endocrinology ,Monoamine neurotransmitter ,Neurology ,chemistry ,NOREPINEPHRINE ,Brain size ,Female ,Down Syndrome ,Neuroscience ,030217 neurology & neurosurgery ,TS65DN MOUSE MODEL ,medicine.drug - Abstract
International audience; Trisomy 21 (T21) or Down syndrome (DS) is the most common genetic disorder associated with intellectual disability and affects around 5 million persons worldwide. Neuroanatomical phenotypes associated with T21 include slight reduction of brain size and weight, abnormalities in several brain areas including spines dysgenesis, dendritic morphogenesis, and early neuroanatomical characteristics of Alzheimer's disease. Monoamine neurotransmitters are involved in dendrites development, functioning of synapses, memory consolidation, and their levels measured in the cerebrospinal fluid, blood, or brain areas that are modified in individuals with T21. DYRK1A is one of the recognized key genes that could explain some of the deficits present in individuals with T21. We investigated by high-performance liquid chromatography with electrochemical detection the contents and processing of monoamines neurotransmitters in four brain areas of female and male transgenic mice for the Dyrk1a gene (mBactgDyrk1a). DYRK1A overexpression induced dramatic deficits in the serotonin contents of the four brain areas tested and major deficits in dopamine and adrenaline contents especially in the hypothalamus. These results suggest that DYRK1A overexpression might be associated with the modification of monoamines content found in individuals with T21 and reinforce the interest to target the level of DYRK1A expression as a therapeutic approach for persons with T21.
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- 2018
7. Rôle des céramides hypothalamiques dans la dérégulation de l’homéostasie glucidique durant l’installation de l’obésité
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H. Le Stunff, Christophe Magnan, Claude Rouch, Mélanie Campana, Kelly Meneyrol, and Lara Bellini
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Nutrition and Dietetics ,Endocrinology, Diabetes and Metabolism ,Internal Medicine - Abstract
Introduction et but de l’etude Des etudes montrent que l’accumulation de lipides dans l’hypothalamus serait responsable de l’installation d’une lipotoxicite centrale. Ce phenomene pourrait jouer un role dans l’apparition d’une insulinoresistance peripherique et du diabete de type 2 en deregulant le controle nerveux de l’homeostasie glucidique. L’accumulation des ceramides est impliquee dans le developpement d’une lipotoxicite des tissus peripheriques. L’objectif de cette etude est de determiner le role du metabolisme des ceramides au niveau hypothalamique dans l’installation d’une insulinoresistance centrale et d’etudier les mecanismes impliques. Nous avons determine le role du metabolisme des ceramides hypothalamiques dans la deregulation de l’homeostasie glucidique induite par l’obesite. Materiel et methodes L’installation d’une insulinoresistance centrale est etudiee a l’aide d’approches in vitro, en utilisant des cellules hypothalamiques de souris GT1-7 traitees avec 1 mM de palmitate (acide gras sature) pendant 24 h. L’insulinoresistance est mesuree par quantification d’Akt phosphorylee (western blot). Les ceramides sont quantifies par lipidomique, l’expression d’ARNm codant pour les genes de la voie de synthese de novo des ceramides par qRT-PCR. Des rats Zucker obeses sont perfuses avec la myriocine (inhibiteur de la synthese de novo des ceramides) en ICV pendant 21 jours. Des tests de sensibilite a l’insuline et de tolerance au glucose sont realises. A la fin du traitement, ils recoivent une injection ICV d’insuline, l’insulinoresistance hypothalamique est mesuree et les ceramides sont quantifies. Les ilots de Langerhans sont isoles pour des tests de secretion d’insuline in vitro. Resultats et analyse statistique Nous avons mis en evidence une insulinoresistance dans la lignee hypothalamique GT1-7 traitees avec le palmitate qui s’accompagne d’une accumulation de ceramides. En presence de myriocine, les ceramides ne sont plus accumules et le l’insulinoresistance induite par le palmitate est contre-carree. L’action insulinoresistante des ceramides a la peripherie est connue pour etre mediee par la PKC ζ. En utilisant un inhibiteur et un virus contre PKC ζ, nous avons egalement montre que le palmitate n’est plus capable d’induire une insulinoresistance et ce malgre la presence d’une accumulation de ceramides. Chez le rat Zucker obese, nous mise en evidence une accumulation de ceramides hypothalamiques qui est contre-carree par la myriocine. Ceci est associe avec une amelioration de la sensibilite a l’insuline dans l’hypothalamus. De facon, interessante, ces animaux ameliorent leur tolerance au glucose associe a une augmentation de la secretion d’insuline. Les ilots de Langerhans isoles a partir de ces rats presentent une capacite secretoire augmentee lors du traitement avec la myriocine. Conclusion Au final, notre etude revele que la lipotoxicite hypothalamique est associee a une accumulation de ceramides dans cette structure, responsable de l’installation d’une insulinoresistance. Ces resultats mettent egalement en evidence le role cle du metabolisme des ceramides au niveau de l’hypothalamus dans la deregulation du controle nerveux de l’homeostasie glucidique induit par l’obesite.
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- 2018
8. Hippocampal lipoprotein lipase regulates energy balance in rodents
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Valentine S. Moullé, Christophe Magnan, Serge Luquet, Katie Ellen Davis, Raphael G. P. Denis, Stephen C. Benoit, Céline Cruciani-Guglielmacci, Sebastien G. Bouret, Sophie Croizier, Julien Castel, Claude Rouch, Hervé Le Stunff, Alexandre Picard, Nicolas Coant, Deborah J. Clegg, Vincent Prevot, and Nadim Kassis
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medicine.medical_specialty ,Lipoprotein lipase ,Neurogenesis ,Hippocampus ,Cell Biology ,Hippocampal formation ,Biology ,Energy homeostasis ,chemistry.chemical_compound ,Endocrinology ,chemistry ,Myriocin ,Internal medicine ,medicine ,Original Article ,lipids (amino acids, peptides, and proteins) ,Molecular Biology ,Tyloxapol ,Ceramide synthase ,medicine.drug - Abstract
Brain lipid sensing is necessary to regulate energy balance. Lipoprotein lipase (LPL) may play a role in this process. We tested if hippocampal LPL regulated energy homeostasis in rodents by specifically attenuating LPL activity in the hippocampus of rats and mice, either by infusing a pharmacological inhibitor (tyloxapol), or using a genetic approach (adeno-associated virus expressing Cre-GFP injected into Lpl (lox/lox) mice). Decreased LPL activity by either method led to increased body weight gain due to decreased locomotor activity and energy expenditure, concomitant with increased parasympathetic tone (unchanged food intake). Decreased LPL activity in both models was associated with increased de novo ceramide synthesis and neurogenesis in the hippocampus, while intrahippocampal infusion of de novo ceramide synthesis inhibitor myriocin completely prevented body weight gain. We conclude that hippocampal lipid sensing might represent a core mechanism for energy homeostasis regulation through de novo ceramide synthesis.
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- 2014
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9. Dietary supplementation withAgaricus blazeimurill extract prevents diet-induced obesity and insulin resistance in rats
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Yorihiko Takeda, Mylène Vincent, Claude Rouch, Nadim Kassis, Patrice D. Cani, Shoji Uchiyama, Stéphanie Migrenne, Christophe Magnan, Nathalie M. Delzenne, Erwann Philippe, Jessica Denom, and Amandine Everard
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medicine.medical_specialty ,Nutrition and Dietetics ,Intra-Abdominal Fat ,biology ,business.industry ,Endocrinology, Diabetes and Metabolism ,Medicine (miscellaneous) ,Adipose tissue ,Inflammation ,Gut flora ,medicine.disease ,biology.organism_classification ,Obesity ,Jejunum ,Endocrinology ,Insulin resistance ,medicine.anatomical_structure ,Internal medicine ,medicine ,medicine.symptom ,business ,Weight gain - Abstract
Dietary supplement may potentially help to fight obesity and other metabolic disorders such as insulin-resistance and low-grade inflammation. The present study aimed to test whether supplementation with Agaricus blazei murill (ABM) extract could have an effect on diet-induced obesity in rats. Wistar rats were fed with control diet (CD) or high-fat diet (HF) and either with or without supplemented ABM for 20 weeks. HF diet-induced body weight gain and increased fat mass compared to CD. In addition HF-fed rats developed hyperleptinemia and insulinemia as well as insulin resistance and glucose intolerance. In HF-fed rats, visceral adipose tissue also expressed biomarkers of inflammation. ABM supplementation in HF rats had a protective effect against body weight gain and all study related disorders. This was not due to decreased food intake which remained significantly higher in HF rats whether supplemented with ABM or not compared to control. There was also no change in gut microbiota composition in HF supplemented with ABM. Interestingly, ABM supplementation induced an increase in both energy expenditure and locomotor activity which could partially explain its protective effect against diet-induced obesity. In addition a decrease in pancreatic lipase activity is also observed in jejunum of ABM-treated rats suggesting a decrease in lipid absorption. Taken together these data highlight a role for ABM to prevent body weight gain and related disorders in peripheral targets independently of effect in food intake in central nervous system.
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- 2013
10. Hypothalamic AgRP-neurons control peripheral substrate utilization and nutrient partitioning
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Julien Castel, Fabienne Foufelle, Julien Dairou, Serge Luquet, Alexandre Prola, Mélissa Flamment, Aurélie Joly-Amado, Renée Ventura-Clapier, Amélie Lacombe, Christophe Magnan, Nadim Kassis, Raphael G. P. Denis, Claude Rouch, Patrice D. Cani, and Céline Cansell
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medicine.medical_specialty ,General Immunology and Microbiology ,General Neuroscience ,digestive, oral, and skin physiology ,Lipid metabolism ,Metabolism ,Carbohydrate metabolism ,Biology ,medicine.disease ,General Biochemistry, Genetics and Molecular Biology ,Nutrient ,Endocrinology ,nervous system ,Hypothalamus ,Diabetes mellitus ,Internal medicine ,medicine ,medicine.symptom ,Molecular Biology ,Weight gain ,Dyslipidemia - Abstract
Obesity-related diseases such as diabetes and dyslipidemia result from metabolic alterations including the defective conversion, storage and utilization of nutrients, but the central mechanisms that regulate this process of nutrient partitioning remain elusive. As positive regulators of feeding behaviour, agouti-related protein (AgRP) producing neurons are indispensible for the hypothalamic integration of energy balance. Here, we demonstrate a role for AgRP-neurons in the control of nutrient partitioning. We report that ablation of AgRP-neurons leads to a change in autonomic output onto liver, muscle and pancreas affecting the relative balance between lipids and carbohydrates metabolism. As a consequence, mice lacking AgRP-neurons become obese and hyperinsulinemic on regular chow but display reduced body weight gain and paradoxical improvement in glucose tolerance on high-fat diet. These results provide a direct demonstration of a role for AgRP-neurons in the coordination of efferent organ activity and nutrient partitioning, providing a mechanistic link between obesity and obesity-related disorders.
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- 2012
11. Palatability Can Drive Feeding Independent of AgRP Neurons
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Pascal Verdié, Michael J. Krashes, Raphael G. P. Denis, Aurélie Joly-Amado, Thomas S. Hnasko, Claude Rouch, Amélie Lacombe, Fanny Langlet, Céline Cansell, E.S. Webber, Marie Schaeffer, Jean-Alain Fehrentz, Sarah Martinez, Ali D. Güler, Serge Luquet, Jean Martinez, Richard D. Palmiter, Bénédicte Dehouck, Stephanie L Padilla, Nadim Kassis, Julien Castel, Christophe Magnan, Anne Sophie Delbès, Unité de Biologie Fonctionnelle et Adaptative (BFA (UMR_8251 / U1133)), Université Paris Diderot - Paris 7 (UPD7)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), National Institutes of Health [Bethesda] (NIH), Centre de Recherche Jean-Pierre AUBERT Neurosciences et Cancer - U1172 Inserm - U837 (JPArc), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Lille Nord de France (COMUE)-Université de Lille, Institut de Génomique Fonctionnelle (IGF), Université de Montpellier (UM)-Université Montpellier 1 (UM1)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Montpellier 2 - Sciences et Techniques (UM2)-Centre National de la Recherche Scientifique (CNRS), University of Washington [Seattle], Institut des Biomolécules Max Mousseron [Pôle Chimie Balard] (IBMM), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM), University of California [San Diego] (UC San Diego), University of California, University of Virginia [Charlottesville], Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), National Institute of Diabetes and Digestive and Kidney Diseases [Bethesda], Centre de Recherche Jean-Pierre AUBERT Neurosciences et Cancer - U837 (JPArc), Université Lille Nord de France (COMUE)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Lille, Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM), Université de Montpellier (UM), University of California (UC), University of Virginia, and KARLI, Mélanie
- Subjects
030309 nutrition & dietetics ,Physiology ,Dopamine ,[SDV]Life Sciences [q-bio] ,Medical Biochemistry and Metabolomics ,Inbred C57BL ,Eating ,Mice ,0302 clinical medicine ,Agouti-Related Protein ,Palatability ,Mice, Knockout ,Neurons ,0303 health sciences ,digestive, oral, and skin physiology ,[SDV] Life Sciences [q-bio] ,medicine.anatomical_structure ,Hypothalamus ,Neurological ,Ghrelin ,medicine.symptom ,hormones, hormone substitutes, and hormone antagonists ,medicine.drug ,Signal Transduction ,Knockout ,Anorexia ,Biology ,Basic Behavioral and Social Science ,Article ,Endocrinology & Metabolism ,03 medical and health sciences ,Orexigenic ,Behavioral and Social Science ,medicine ,Biological neural network ,Animals ,Obesity ,Molecular Biology ,Nutrition ,030304 developmental biology ,Neurosciences ,Cell Biology ,Mice, Inbred C57BL ,nervous system ,Biochemistry and Cell Biology ,Neuron ,Neuroscience ,030217 neurology & neurosurgery - Abstract
International audience; Feeding behavior is exquisitely regulated by homeostatic and hedonic neural substrates that integrate energy demand as well as the reinforcing and rewarding aspects of food. Understanding the net contribution of homeostatic and reward-driven feeding has become critical because of the ubiquitous source of energy-dense foods and the consequent obesity epidemic. Hypothalamic agouti-related peptide-secreting neurons (AgRP neurons) provide the primary orexigenic drive of homeostatic feeding. Using models of neuronal inhibition or ablation, we demonstrate that the feeding response to a fast ghrelin or serotonin receptor agonist relies on AgRP neurons. However, when palatable food is provided, AgRP neurons are dispensable for an appropriate feeding response. In addition, AgRP-ablated mice present exacerbated stress-induced anorexia and palatable food intake--a hallmark of comfort feeding. These results suggest that, when AgRP neuron activity is impaired, neural circuits sensitive to emotion and stress are engaged and modulated by food palatability and dopamine signaling.
- Published
- 2015
12. Chronic central leptin infusion differently modulates brain and liver insulin signaling
- Author
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Claude Rouch, Flavien Berthou, Mohammed Taouis, Kyriaki Gerozissis, Arieh Gertler, Centre de Neurosciences Paris-Sud (CNPS), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de physiopathologie de la nutrition (LPN), Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), and Food Science, and Nutrition, Faculty of Agricultural, Food and Environmental Quality Sciences
- Subjects
Blood Glucose ,Leptin ,Male ,Transcription, Genetic ,medicine.medical_treatment ,Weight Gain ,environment and public health ,Biochemistry ,Eating ,0302 clinical medicine ,Endocrinology ,Insulin receptor substrate ,Insulin ,Phosphorylation ,Protein Tyrosine Phosphatase, Non-Receptor Type 1 ,0303 health sciences ,biology ,digestive, oral, and skin physiology ,Brain ,Recombinant Proteins ,Liver ,[SDV.NEU]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC] ,hormones, hormone substitutes, and hormone antagonists ,STAT3 Transcription Factor ,medicine.medical_specialty ,030209 endocrinology & metabolism ,03 medical and health sciences ,Insulin resistance ,Downregulation and upregulation ,Internal medicine ,medicine ,Animals ,RNA, Messenger ,Molecular Biology ,030304 developmental biology ,Leptin receptor ,business.industry ,medicine.disease ,Receptor, Insulin ,Rats ,enzymes and coenzymes (carbohydrates) ,Insulin receptor ,Insulin Receptor Substrate Proteins ,biology.protein ,business ,Proto-Oncogene Proteins c-akt - Abstract
International audience; Recent studies reported the impact of leptin on peripheral insulin sensitivity and glucose utilization. However, little is known concerning the effect of central leptin on hypothalamic and hepatic insulin efficiency. This study aimed to determine the consequence of chronic intra-cerebroventricular (ICV) leptin or murine leptin antagonist (MLA) infusion on hypothalamic and hepatic insulin signaling pathways, in rats. A 2-week central leptin infusion enhanced insulin-dependent Akt phosphorylation in the liver without changing PTP-1B protein expression, associated to insulin receptor (IR) upregulation and reduced IRS-1 phosphorylation on Ser302 residue. In the hypothalamus, a chronic ICV leptin infusion induced PTP-1B associated with a specific decrease in insulin-dependent Akt phosphorylation. In contrast, a chronic MLA infusion did not alter IR and PTP-1B expressions in hypothalamus and liver. Our results underline a brain leptin-dependent increase in hepatic insulin efficiency as mirrored by IR up-regulation, increased insulin-dependent Akt phosphorylation and reduced IRS-1 phosphorylation on Ser302 residue.
- Published
- 2011
13. Comparative effects of Citrullus colocynthis, sunflower and olive oil-enriched diet in streptozotocin-induced diabetes in rats
- Author
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Céline Cruciani-Guglielmacci, Claude Rouch, Christophe Magnan, M.-F. Berthault, D Chabane Sari, N Sebbagh, and F Ouali
- Subjects
Blood Glucose ,Male ,medicine.medical_specialty ,food.ingredient ,endocrine system diseases ,Endocrinology, Diabetes and Metabolism ,Type 2 diabetes ,Diabetes Mellitus, Experimental ,Citrullus ,Endocrinology ,food ,Insulin resistance ,Animal science ,Citrullus colocynthis ,Insulin-Secreting Cells ,Internal medicine ,Diabetes mellitus ,Internal Medicine ,medicine ,Animals ,Insulin ,Plant Oils ,Rats, Wistar ,Olive Oil ,biology ,business.industry ,Sunflower oil ,nutritional and metabolic diseases ,General Medicine ,biology.organism_classification ,medicine.disease ,Streptozotocin ,Sunflower ,Rats ,Helianthus ,business ,medicine.drug - Abstract
Citrullus colocynthis (colocynth) seeds are traditionally used as antidiabetic medication in Mediterranean countries. The present study evaluated the differential effects of diets enriched with C. colocynthis, sunflower or olive oils on the pancreatic beta-cell mass in streptozotocin (STZ)-induced diabetes in rats. STZ injection induced rapid hyperglycaemia in all animals. However, 2 months later, hyperglycaemia was significantly less pronounced in the rats fed a C. colocynthis oil-enriched diet compared with other rat groups (7.9mM versus 12mM and 16mM with colocynth versus olive and sunflower oils, respectively). Assessment of insulin sensitivity using the homoeostasis model assessment (HOMA) method also indicated less insulin resistance in the rats fed a C. colocynthis oil-enriched diet versus the other rats. Finally, 2 months after STZ injection, the pancreatic beta-cell mass was similar in both the STZ-treated rats fed the colocynth oil-enriched diet and their controls fed the same diet. In contrast, the pancreatic beta-cell mass remained lower in the STZ-induced diabetic rats fed with olive oil- and sunflower oil-enriched diets compared with the C. colocynthis group. We conclude that C. colocynthis oil supplementation may have a beneficial effect by partly preserving or restoring pancreatic beta-cell mass in the STZ-induced diabetes rat model.
- Published
- 2009
14. Influence de l’obésité sur les phénomènes neurodégénératifs
- Author
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Claude Rouch, Palaniyandi Ravanan, C. Lefebvre d’Hellencourt, Groupe d'Etude sur l'Inflammation Chronique et l'Obésité (GEICO), Université de La Réunion (UR), and Laboratoire de Biochimie et Génétique Moléculaire (LBGM)
- Subjects
medicine.medical_specialty ,Quality of Life Research ,Neurogenesis ,Medicine/Public Health ,Tissu adipeux ,03 medical and health sciences ,Endocrinology ,0302 clinical medicine ,Metabolic Diseases ,Medicine ,Obésité ,Obesity ,Neurodegeneration ,ComputingMilieux_MISCELLANEOUS ,030304 developmental biology ,Inflammation ,Gynecology ,0303 health sciences ,Nutrition and Dietetics ,business.industry ,Diabetes ,Nutritional status ,General Medicine ,Neurodégénérescence ,adipose tissue ,general ,Medicine public health ,Neurogenèse ,business ,[SDV.MHEP]Life Sciences [q-bio]/Human health and pathology ,030217 neurology & neurosurgery ,Public Health/Gesundheitswesen - Abstract
Differents elements exterieurs au systeme nerveux central (SNC) peuvent influencer son fonctionnement et sa reponse a des agressions. D’une part, l’alimentation, selon sa composition, peut augmenter ou diminuer les risques de neurodegenerescence. D’autre part, des etudes epidemiologiques et des experiences sur des modeles animaux montrent que le surpoids et l’obesite augmentent le risque de developper des maladies neurodegeneratives (Alzheimer, Parkinson…) ainsi que la susceptibilite a des neurodegenerescences aigues (traumatisme, ischemie, chimique…). La neurogenese constitutive ou induite dans le SNC adulte represente un espoir therapeutique permettant de compenser les pertes liees aux phenomenes neurodegeneratifs. Cependant, meme s’il a ete montre que l’alimentation peut affecter la production de nouveaux neurones, l’influence de l’exces de tissu adipeux sur la neurogenese n’est pas encore determinee.
- Published
- 2008
15. Fatty Acid Signaling in the Hypothalamus and the Neural Control of Insulin Secretion
- Author
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Ruokun Wang, Claude Rouch, Alain Ktorza, Barry E. Levin, Ling Kang, Céline Cruciani-Guglielmacci, Anne-Laure Lefèvre, Christophe Magnan, Vanessa H. Routh, and Stéphanie Migrenne
- Subjects
medicine.medical_specialty ,Sympathetic nervous system ,Endocrinology, Diabetes and Metabolism ,Insulin ,medicine.medical_treatment ,Central nervous system ,Biology ,Splanchnic nerves ,Energy homeostasis ,Endocrinology ,medicine.anatomical_structure ,Internal medicine ,Internal Medicine ,medicine ,Premovement neuronal activity ,Secretion ,Pancreatic hormone - Abstract
It is now clearly demonstrated that fatty acids (FAs) may modulate neural control of energy homeostasis and specifically affect both insulin secretion and action. Indeed, pancreatic β-cells receive rich neural innervation and FAs induce important changes in autonomic nervous activity. We previously reported that chronic infusion of lipids decreased sympathetic nervous system activity and led to exaggerated glucose-induced insulin secretion (GIIS), as would be expected from the known inhibitory effect of sympathetic splanchnic nerve activity on insulin secretion. Intracarotid infusion of lipids that do not change plasma FA concentrations also lead to increased GIIS. This effect of FAs on GIIS was prevented by inhibition of β-oxidation. It is noteworthy that a single intracarotid injection of oleic acid also induced a transient increase in plasma insulin without any change in plasma glucose, suggesting that FAs per se can regulate neural control of insulin secretion. Finally, using whole cell current clamp recordings in hypothalamic slices and calcium imaging in dissociated hypothalamic neurons, we identified a hypothalamic subpopulation of neurons either excited (13%) or inhibited (6%) by FAs. Thus, FAs per se or their metabolites modulate neuronal activity, as a means of directly monitoring ongoing fuel availability by central nervous system nutrient-sensing neurons involved in the regulation of insulin secretion.
- Published
- 2006
16. Dietary triglycerides act on mesolimbic structures to regulate the rewarding and motivational aspects of feeding
- Author
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Brian Finan, Robert H. Eckel, S E la Fleur, Thomas S. Hnasko, Céline Cansell, Anne-Sophie Delbes, Matthias H. Tschöp, D. Mestivier, Raphael G. P. Denis, Julien Castel, Serge Luquet, Merel Rijnsburger, Sarah Martinez, Claude Rouch, Ralph J. DiLeone, Jaime G. Maldonado-Avilés, Christophe Magnan, Unité de Biologie Fonctionnelle et Adaptative (BFA (UMR_8251 / U1133)), Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Institut Jacques Monod (IJM (UMR_7592)), Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Helmholtz Zentrum München = German Research Center for Environmental Health, Department of Psychiatry and Neurobiology [New Haven, CT, USA], Yale University [New Haven], University of Amsterdam [Amsterdam] (UvA), University of Colorado Anschutz [Aurora], Department of Neurosciences [Univ California San Diego] (Neuro - UC San Diego), School of Medicine [Univ California San Diego] (UC San Diego), University of California [San Diego] (UC San Diego), University of California (UC)-University of California (UC)-University of California [San Diego] (UC San Diego), University of California (UC)-University of California (UC), CANSELL, Celine, Endocrinology Laboratory, Endocrinology, AGEM - Amsterdam Gastroenterology Endocrinology Metabolism, ANS - Amsterdam Neuroscience, and Amsterdam Neuroscience - Neuroinfection & -inflammation
- Subjects
Male ,medicine.medical_specialty ,Carotid arteries ,[SDV]Life Sciences [q-bio] ,Nucleus accumbens ,Motor Activity ,Inbred C57BL ,Basic Behavioral and Social Science ,Medical and Health Sciences ,Article ,Cellular and Molecular Neuroscience ,Mice ,Reward ,Dopamine ,Internal medicine ,Behavioral and Social Science ,medicine ,Animals ,Obesity ,Amphetamine ,Molecular Biology ,Triglycerides ,Nutrition ,Psychiatry ,Lipoprotein lipase ,Motivation ,Psychology and Cognitive Sciences ,Neurosciences ,Brain ,Lipid metabolism ,Metabolism ,Feeding Behavior ,Biological Sciences ,Mice, Inbred C57BL ,[SDV] Life Sciences [q-bio] ,Psychiatry and Mental health ,Lipoprotein Lipase ,Endocrinology ,Carotid Arteries ,Targeted disruption ,Central Nervous System Stimulants ,Psychology ,medicine.drug - Abstract
International audience; Circulating triglycerides (TGs) normally increase after a meal but are altered in pathophysiological conditions, such as obesity. Although TG metabolism in the brain remains poorly understood, several brain structures express enzymes that process TG-enriched particles, including mesolimbic structures. For this reason, and because consumption of high-fat diet alters dopamine signaling, we tested the hypothesis that TG might directly target mesolimbic reward circuits to control reward-seeking behaviors. We found that the delivery of small amounts of TG to the brain through the carotid artery rapidly reduced both spontaneous and amphetamine-induced locomotion, abolished preference for palatable food and reduced the motivation to engage in food-seeking behavior. Conversely, targeted disruption of the TG-hydrolyzing enzyme lipoprotein lipase specifically in the nucleus accumbens increased palatable food preference and food-seeking behavior. Finally, prolonged TG perfusion resulted in a return to normal palatable food preference despite continued locomotor suppression, suggesting that adaptive mechanisms occur. These findings reveal new mechanisms by which dietary fat may alter mesolimbic circuit function and reward seeking.
- Published
- 2014
17. Is TAP2*0102 allele involved in insulin-dependent diabetes mellitus (type 1) protection?
- Author
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Christine Robert, Michel Pabion, Claude Rouch, Frédéric Cadet, Maya Cesari, Henri Caillens, and Jean-Jacques Hoarau
- Subjects
Linkage disequilibrium ,endocrine system diseases ,Genes, MHC Class II ,Immunology ,Population ,Human leukocyte antigen ,Biology ,HLA-DQ alpha-Chains ,Linkage Disequilibrium ,Gene Frequency ,ATP Binding Cassette Transporter, Subfamily B, Member 3 ,HLA Antigens ,HLA-DQ Antigens ,Genetic predisposition ,HLA-DQ beta-Chains ,Humans ,Immunology and Allergy ,ATP Binding Cassette Transporter, Subfamily B, Member 2 ,Allele ,First-degree relatives ,education ,Family Health ,Genetics ,education.field_of_study ,HLA-DQB1 ,Haplotype ,nutritional and metabolic diseases ,HLA-DR Antigens ,General Medicine ,Telomere ,DNA Fingerprinting ,Diabetes Mellitus, Type 1 ,Haplotypes ,ATP-Binding Cassette Transporters ,HLA-DRB1 Chains - Abstract
In this study, we have investigated the frequencies of TAP1 and TAP2 alleles in a group of 226 persons, living in La Reunion Island, consisting of 70 patients with insulin-dependent diabetes mellitus (IDDM) and most of their first degree relatives ( i.e. , 156 parents and full sibling subjects) and previously HLA DQB1, DQA1, and DRB1 genotyped. The population of this island is constituted by a particular structure of highly crossbreeding people. Interestingly, the new TAP2*0104 allele, previously discovered by our team in Reunion Island, was found to be increased in the IDDM population and the calculated HRR was relatively high (HRR = 3.3). This result seems to be due to a positive linkage disequilibrium between TAP2*0104 allele and the highly diabetogenous DQB1* 0201–DQA1* 0501–DRB1 0301 haplotype (HRR = 9), which suggests that TAP2*0104 cannot be considered as an additional predispositional factor, but more as a genetic susceptibility marker of IDDM. In addition, we show that minor alleles (TAP2D, *0102, *0103, *0104) are associated with a restricted number of HLA DQ-DR haplotypes and each of them exhibits a preferential linkage with one particular haplotype. In contrast with other alleles, and despite a HRR value close to 1, we show that TAP2*0102 allele contributes significantly to a drastic reduction of the diabetogenic effect of DQB1*0201–DQA1*0301.1–DRB*0701 haplotype. Indeed, this haplotype, which is usually preferentially transmitted to affected children, is dominantly transmitted to healthy children when it is associated with TAP2*0102. Therefore, this allele seems to contribute to genetic protection to IDDM.
- Published
- 2004
18. Assessment of the C4 phosphoenolpyruvate carboxylase gene diversity in grasses (Poaceae)
- Author
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Bernard Offmann, Claude Rouch, Frédéric Cadet, G. Besnard, and Christine Robert
- Subjects
Genetics ,Phylogenetic tree ,food and beverages ,General Medicine ,Biology ,biology.organism_classification ,Homology (biology) ,Phylogenetics ,Panicoideae ,Complementary DNA ,Botany ,Chloridoideae ,Arundinoideae ,Phosphoenolpyruvate carboxylase ,Agronomy and Crop Science ,Biotechnology - Abstract
C(4) phosphoenolpyruvate carboxylase (PEPC) is a key enzyme in the C(4) photosynthetic pathway. To analyze the diversity of the corresponding gene in grasses, we designed PCR primers to specifically amplify C(4) PEPC cDNA fragments. Using RT-PCR, we generated partial PEPC cDNA sequences in several grasses displaying a C(4) photosynthetic pathway. All these sequences displayed a high homology (78-99%) with known grass C(4) PEPCs. PCR amplification did not occur in two grasses that display the C(3) photosynthetic pathway, and therefore we assumed that all generated sequences corresponded to C(4) PEPC transcripts. Based on one large cDNA segment, phylogenetic reconstruction enabled us to assess the relationships between 22 grass species belonging to the subfamilies Panicoideae, Arundinoideae and Chloridoideae. The phylogenetic relationships between species deduced from C(4) PEPC sequences were similar to those deduced from other molecular data. The sequence evolution of the C(4) PEPC isoform was faster than in the other PEPC isoforms. Finally, the utility of the C(4) PEPC gene phylogeny to study the evolution of C(4) photosynthesis in grasses is discussed.
- Published
- 2002
19. Behavioral responses to ingestion of different sources of fat. Involvement of serotonin?
- Author
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Claude Rouch, Valérie Daugé, and Martine Orosco
- Subjects
Male ,Serotonin ,Sucrose ,food.ingredient ,Satiety Response ,Behavioral Neuroscience ,chemistry.chemical_compound ,Neurochemical ,food ,Nutrient ,Animals ,Ingestion ,Food science ,Rats, Wistar ,chemistry.chemical_classification ,Meal ,Chemistry ,Sunflower oil ,digestive, oral, and skin physiology ,food and beverages ,Dietary Fats ,Rats ,Fatty Acids, Unsaturated ,Composition (visual arts) ,Arousal ,Polyunsaturated fatty acid - Abstract
In previous experiments, we described a decrease in extracellular hypothalamic serotonin, 5-hydroxy-tryptamine (5-HT), in response to ingestion of a lard meal. This effect was related to the low satiating potency of lard as compared with other nutrients. Since the composition in fatty acids might be important for these effects, the purpose of this study was to analyze the neurochemical and behavioral responses to ingestion of different sources of fat. Unique meals of three margarines used in human feeding were compared with a meal of lard with regard to their effects on hypothalamic 5-HT, satiety, anxiety-like behavior and sucrose consumption. A vegetable margarine with a high content in saturated fatty acids also decreased hypothalamic 5-HT while ingestion of a sunflower oil and an olive oil enriched margarines, both high in polyunsaturated fatty acids, did not affect significantly 5-HT levels. However, these two last ones were not the most satiating. The olive oil margarine induced a tendency to an anxiety-like behavior while lard increased sucrose consumption. Thus, ingestion of fats may alter specifically behavioral responses. The involvement of 5-HT is likely in the case of lard ingestion but probably not for the other sources of fat.
- Published
- 2002
20. Effects of Pure Macronutrient Ingestion on Plasma Tryptophan and Large Neutral Amino Acids
- Author
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Claude Rouch, S. Nicolaidis, and Martine Orosco
- Subjects
Male ,0301 basic medicine ,Time Factors ,Medicine (miscellaneous) ,Fatty Acids, Nonesterified ,03 medical and health sciences ,0302 clinical medicine ,Casein ,Animals ,Ingestion ,Rats, Wistar ,chemistry.chemical_classification ,Meal ,Nutrition and Dietetics ,Chemistry ,General Neuroscience ,Tryptophan ,General Medicine ,Carbohydrate ,Animal Feed ,Diet ,Rats ,Amino acid ,Kinetics ,Amino Acids, Neutral ,030104 developmental biology ,Biochemistry ,Composition (visual arts) ,Serotonin ,030217 neurology & neurosurgery - Abstract
The role of tryptophan and its competitor large neutral amino acids, proposed earlier for serotonin synthesis following carbohydrate or protein ingestion, was reassessed in relation to a recent study investigating serotonin release, including the so far unknown effects of fats. In the present study, meals of either carbohydrates, casein, or lard, were supplied to rats for 30 min and blood samples collected every 15 min to follow the changes in plasma large neutral amino acids. In response to carbohydrates, amino acid levels fell and the ratio tryptophan over sum of other amino acids increased. Following casein ingestion, all amino acids were enhanced, tryptophan somewhat less, leading to a decreased ratio. The lard meal induced a slight decrease in some amino acids while the ratio remained constant. Only in response to casein, and partly to carbohydrates, did a consistent relation appear between the previously observed serotonin changes and the ratio. These data suggest that a relationship between the ratio and the previously observed serotonin changes is not always encountered because the release is not obligatorily coupled to synthesis and is subject to behavioral influences. It remains that serotonin release is affected by the composition of the meal through peripheral metabolic mechanisms.
- Published
- 2001
21. [Untitled]
- Author
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Stéphanie Lemierre, Stylianos Nicolaidis, Claude Rouch, Martine Orosco, and Kyriaki Gerozissis
- Subjects
medicine.medical_specialty ,Microdialysis ,Insulin ,medicine.medical_treatment ,Stimulation ,Cell Biology ,General Medicine ,Biology ,medicine.disease ,Obesity ,Cellular and Molecular Neuroscience ,Endocrinology ,In vivo ,Hypothalamus ,Internal medicine ,medicine ,Extracellular ,Serotonin - Abstract
1. Hypothalamic insulin (HI) is well known for its role in feeding regulation. In addition, its concentration is modified in response to meals. Recent studies suggest that brain insulin participates in memory processes, possibly through stimulation by glucose. 2. The present microdialysis study focused on local in vivo regulation of HI by glucose and on the effects of aging on HI, since aging is characterized by deterioration of memory, body weight regulation, and central glucose utilization. Glucose (8 mM) infused for 5 min increased extracellular HI levels rapidly, by 4.6-fold, and cerebellar insulin levels by 0.4-fold only, suggesting a specific area-dependent regulation of HI by glucose. Neither insulinemia nor glycemia were affected, suggesting a central mechanism. The same dose of glucose induced a modest (0.4-fold), delayed (45 min) increase in hypothalamic serotonin, suggesting that the effect of glucose on HI is independent of a previously defined local serotonin-induced insulin release. HI levels in old normal weight rats were half the levels of young rats. In genetically old obese (fa/fa) Zucker rats, HI concentration was 30% of that in young normal rats, suggesting a deterioration of HI availability when aging and obesity are combined. 3. The above results, in line with recent considerations on a potential role of central insulin in learning and memory, suggest particular effects of HI on feeding and memory and probably on a specific "memory for food."
- Published
- 2001
22. Unsaturated fatty acids disrupt Smad signaling in gonadotrope cells leading to inhibition of FSHβ gene expression
- Author
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Julien Dairou, Violaine Simon, Chantal Denoyelle, Muhammad Ishaq, Stéphanie Migrenne, Joëlle Cohen-Tannoudji, Ghislaine Garrel, Christophe Magnan, Céline Cruciani-Guglielmacci, and Claude Rouch
- Subjects
Male ,endocrine system ,medicine.medical_specialty ,Small interfering RNA ,medicine.drug_class ,Linoleic acid ,Gene Expression ,Smad Proteins ,Gonadotrophs ,Gonadotropic cell ,FSHB ,Linoleic Acid ,chemistry.chemical_compound ,Endocrinology ,Internal medicine ,Gene expression ,medicine ,Animals ,Rats, Wistar ,Promoter Regions, Genetic ,Cells, Cultured ,chemistry.chemical_classification ,biology ,Fatty acid ,Rats ,Fatty acid synthase ,chemistry ,Follicle Stimulating Hormone, beta Subunit ,biology.protein ,Fatty Acids, Unsaturated ,Gonadotropin ,Signal Transduction - Abstract
Reproductive function is highly dependent on nutritional input. We recently provided evidence that the unsaturated ω6 fatty acid (FA), linoleic acid (linoleic), interferes with transcription and secretion of the gonadotropin LH, highlighting the existence of a lipid sensing in pituitary gonadotropes. Here, we show, using a combination of in vivo and in vitro models, that linoleic differentially regulates Lhb and Fshb expression. Central exposure of rats to linoleic over 7 days was associated with increase of Lhb but not Fshb transcript levels. Consistently, exposure of rat pituitary cells or LβT2 cells to linoleic increased Lhb, whereas it dramatically decreased Fshb transcript levels without affecting its stability. This effect was also induced by ω9 and ω3-polyunsaturated FA but not by saturated palmitic acid. Analysis of the underlying mechanisms in LβT2 cells using small interfering RNA revealed that early growth response protein 1 mediates linoleic stimulation of Lhb expression. Furthermore, we demonstrated that linoleic counteracts activin and bone morphogenetic protein-2 stimulation of Fshb expression. Using Western blotting and Smad-responsive reporter gene assays, linoleic was shown to decrease basal Smad2/3 phosphorylation levels as well as activin- and bone morphogenetic protein-2-dependent activation of Smad, uncovering a new FA-sensitive signaling cascade. Finally, the protein phosphatase magnesium-dependent 1A was shown to mediate linoleic inhibition of basal Smad phosphorylation and Fshb expression, identifying protein phosphatase magnesium-dependent 1A as a new target of FA in gonadotropes. Altogether, this study provides a novel mechanism by which FAs target gene expression and underlines the relevant role of pituitary gonadotropes in mediating the effects of nutritional FA on reproductive function.
- Published
- 2013
23. Determination, Using Microdialysis, of Hypothalamic Serotonin Variations in Response to Different Macronutrients
- Author
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Martine Orosco, Stylianos Nicolaidis, and Claude Rouch
- Subjects
Male ,Serotonin ,medicine.medical_specialty ,Microdialysis ,Sucrose ,Hypothalamus ,Experimental and Cognitive Psychology ,Biology ,Serotonergic ,Satiety Response ,Behavioral Neuroscience ,chemistry.chemical_compound ,Internal medicine ,Dietary Carbohydrates ,medicine ,Extracellular ,Animals ,Ingestion ,Rats, Wistar ,Meal ,digestive, oral, and skin physiology ,Carbohydrate ,Dietary Fats ,Rats ,Kinetics ,Endocrinology ,chemistry ,Female ,Dietary Proteins - Abstract
In response to a chow meal in rats, we observed previously in PVN-VMH dialysates, an increase in serotonin (5-HT) that could be related to satiety or to metabolic consequences of the composition of the meal. Indeed, carbohydrates are admitted to increase 5-HT synthesis while proteins decrease it, but the time course and mechanisms of these effects were not known. For that purpose, pure carbohydrates, proteins, or fats were offered for 30 min and the changes in 5-HT from PVN-VMH dialysates were followed. Carbohydrates (85% starch + 15% sucrose) enhanced 5-HT levels as soon as the first 15 min of feeding, with a maximum 60 min later. Conversely, protein ingestion induced in the second 15 min of the meal, a decrease in 5-HT that lasted 2 h. During a fat meal (lard), 5-HT levels also decreased at the beginning of the meal and remained low during 45 min. The present data reassess the previous theories on the serotonergic effects of specific macronutrient ingestion. The effect of a fat meal on 5-HT levels had never been described so far. The increase in 5-HT in response to a carbohydrate meal is further specified. The 5-HT decrease induced by proteins, in agreement with the previous theories, is better explained now by using pure protein diets and extracellular 5-HT assay. However, all the changes observed start too early to be only metabolic in origin. Other mechanisms may occur, including the release of 5-HT in response to a meal to induce satiety.
- Published
- 1998
24. Microquantification of Proteins by Spectrophotometry. Part I: From 190 nm to 1100 nm, Selection of Wavelengths
- Author
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Claude Rouch, Michel Pabion, Frédéric Cadet, Pascal Baret, and Ariane Angeloff
- Subjects
Chromatography ,medicine.diagnostic_test ,Chemistry ,Analytical chemistry ,Atomic and Molecular Physics, and Optics ,Analytical Chemistry ,Absorbance ,Wavelength ,Reagent ,Coomassie blue ,Spectrophotometry ,medicine ,Bicinchoninic acid assay ,Correlation factor ,Correlation factors ,Spectroscopy - Abstract
Several methods for protein determination have been described. In almost all cases, a detection reagent is involved (Coomassie Blue reagent, bicinchoninic acid, Folin reagent). Proteins quantification determination by measurements in the U.V. region1 have been abandonned because of the weak sensitivity of the apparatus (concentrations of the order of 100 μg/ml) and because of the lack of precision at low wavelengths (far U.V.). Owing to the progress in the performance of equipments, (i) we have been able to show that the reliability of current equipments allowed measurements in the more sensitivity range of proteins (190 to 220 nm) and beyond (220 to 1100 nm) and (ii) we have hence calculated the correlation factors between absorbance values and wavelengths for 17 proteins. It was found that 190 nm and 277 nm were the best wavelengths in far U.V. region for the protein quantification (correlation factor respectively of 0.69 and 0.62). The concentrations of 16 proteins were predicted at 190 nm and...
- Published
- 1997
25. Inhibition of palmito (Acanthophoenix rubra) polyphenol oxidase by carboxylic acids
- Author
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Claude Rouch, Frédéric Cadet, and Christine Robert
- Subjects
chemistry.chemical_classification ,Double bond ,biology ,Stereochemistry ,General Medicine ,biology.organism_classification ,Inhibitory postsynaptic potential ,Polyphenol oxidase ,Medicinal chemistry ,Cinnamic acid ,Analytical Chemistry ,chemistry.chemical_compound ,chemistry ,Sorbic acid ,Benzene ,Acanthophoenix rubra ,Food Science ,Benzoic acid - Abstract
The inhibition of palmito (Acanthophoenix rubra) polyphenol oxidase (PPO) is reported. Recently, two forms of palmito PPO were partially purified by hydrophobic chromatography. Inhibitory effects of various carboxylic acids on these two forms have been studied. Both forms showed identical behaviour towards the inhibitors studied. Cinnamic acid was found to have the greatest inhibitory effect (Ki = 0·06 mM). When the inhibitory effects of acids from the benzoic acid family and from the cinnamic acid family were compared, it was found that acids which possess a double bond between the benzene ring and the carboxylic function showed the highest inhibitory effect. This inhibitory effect was decreased by substitutions on the benzene ring. The influence of pH on the inhibitory effect of carboxylic acids on palmito PPO has also been investigated. Ki decreased with a decrease in pH. This effect is due to the fact that it is only the undissociated form (AH) of carboxylic acids that is responsible for inhibition of PPO. Inhibition constants (Ki for the AH form have been recalculated and were found to remain constant in the pH range studied (for benzoic acid Ki = 0·14 mM, for cinnamic acid Ki = 0·019 mM, for sorbic acid Ki = 0·15 mM).
- Published
- 1997
26. Kinetic Study of the Irreversible Thermal Deactivation of Palmito (Acanthophoenix rubra) Polyphenol Oxidase and Effect of pH
- Author
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Claude Rouch, Michel Pabion, Florence Richard-Forget, Frédéric Cadet, and Christine Robert
- Subjects
0106 biological sciences ,Arrhenius equation ,biology ,Standard molar entropy ,Chemistry ,Stereochemistry ,Enthalpy ,Substrate (chemistry) ,04 agricultural and veterinary sciences ,General Chemistry ,Activation energy ,biology.organism_classification ,040401 food science ,01 natural sciences ,Standard enthalpy of formation ,symbols.namesake ,chemistry.chemical_compound ,0404 agricultural biotechnology ,Pyrogallol ,010608 biotechnology ,symbols ,Physical chemistry ,General Agricultural and Biological Sciences ,Acanthophoenix rubra - Abstract
The optimal temperature of palmito (Acanthophoenix rubra) polyphenol oxidase (PPO) is 30 degrees C. The Arrhenius activation energy was calculated to be 5.41 kJ mol(-1). Standard enthalpy of the reaction is -60.99 kJ mol(-1). At 25 degrees C, standard free energy and standard entropy were, respectively, 16.75 kJ mol(-1) and -260.87 J mol(-1) K(-1). The enzyme heated at temperatures above 30 degrees C loses its activity. Fifty percent inhibition is reached in 18 min at 70 degrees C, in 8 min at 75 degrees C, and in 2.5 min at 80 degrees C. The kinetics of the thermal irreversible denaturation of this enzyme is characterized by two steps: N leads to X(Td) leads to D, where N represents the native form, X represents an intermediate form, the structure of which depends on the deactivation temperature Td, and D is the completely denatured form of the enzyme. Our experimental results rule out a two-isoenzyme (with varying heat sensitivity) model. The thermodynamic parameters of the irreversible denaturation of the intermediate form were 102.70 and 97.10 kJ mol(-1) for activation enthalpy and activation energy, respectively, and 16.85 J mol(-1) K(-1) for activation entropy at 60 degrees C. Furthermore, this paper describes the effect of pH on the activity of the PPO. Studies were carried out with 4-methylcatechol and pyrogallol as substrates. The pH profile was not a function of the nature of the substrate assayed. The pH optimum was 5.2. The plot of logVmax app vs pH indicates that the oxidation of the substrates depended of the ionization of two groups in the enzyme-substrate complex with apparent pK values of 3.06 and 7.29 and 3.44 and 7.12, respectively, for 4-methylcatechol and pyrogallol. The very slight differences between the values suggest the existence of only one site on the molecule for both substrates.
- Published
- 1995
27. Dietary Supplementation With Agaricus Blazei Murill Extract Prevents Diet-Induced Obesity and Insulin Resistance in Rats
- Author
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Mylène Vincent, Erwann Philippe, Amandine Everard, Nadim Kassis, Claude Rouch, Jessica Denom, Yorihiko Takeda, Shoji Uchiyama, Nathalie M. Delzenne, Patrice D. Cani, Stéphanie Migrenne, and Christophe Magnan
- Subjects
Blood Glucose ,Leptin ,Male ,Agaricus ,Endocrinology, Diabetes and Metabolism ,Medicine (miscellaneous) ,Intra-Abdominal Fat ,Diet, High-Fat ,Weight Gain ,Endocrinology ,Glucose Intolerance ,Animals ,Insulin ,Obesity ,Rats, Wistar ,Inflammation ,Nutrition and Dietetics ,Microbiota ,Probiotics ,Calorimetry, Indirect ,Lipase ,Dietary Fats ,Subcutaneous Fat, Abdominal ,Rats ,Gastrointestinal Tract ,Dietary Supplements ,Body Composition ,Insulin Resistance ,Energy Metabolism ,Biomarkers - Abstract
Dietary supplement may potentially help to fight obesity and other metabolic disorders such as insulin-resistance and low-grade inflammation. The present study aimed to test whether supplementation with Agaricus blazei murill (ABM) extract could have an effect on diet-induced obesity in rats.Wistar rats were fed with control diet (CD) or high-fat diet (HF) and either with or without supplemented ABM for 20 weeks.HF diet-induced body weight gain and increased fat mass compared to CD. In addition HF-fed rats developed hyperleptinemia and insulinemia as well as insulin resistance and glucose intolerance. In HF-fed rats, visceral adipose tissue also expressed biomarkers of inflammation. ABM supplementation in HF rats had a protective effect against body weight gain and all study related disorders. This was not due to decreased food intake which remained significantly higher in HF rats whether supplemented with ABM or not compared to control. There was also no change in gut microbiota composition in HF supplemented with ABM. Interestingly, ABM supplementation induced an increase in both energy expenditure and locomotor activity which could partially explain its protective effect against diet-induced obesity. In addition a decrease in pancreatic lipase activity is also observed in jejunum of ABM-treated rats suggesting a decrease in lipid absorption.Taken together these data highlight a role for ABM to prevent body weight gain and related disorders in peripheral targets independently of effect in food intake in central nervous system.
- Published
- 2012
28. Hypothalamic serotonin-insulin signaling cross-talk and alterations in a type 2 diabetic model
- Author
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Nicolas Vicaire, Eirini M. Markaki, Ioannis K. Papazoglou, D. Bailbé, Claude Rouch, Flavien Berthou, Kyriaki Gerozissis, Bernard Portha, Mohammed Taouis, Centre de Neurosciences Paris-Sud (CNPS), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de physiopathologie de la nutrition (LPN), Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Laboratoire B2PE, Unité BFA, and Université Paris Descartes - Paris 5 (UPD5)
- Subjects
Blood Glucose ,Leptin ,Male ,medicine.medical_treatment ,Type 2 diabetes ,Biochemistry ,chemistry.chemical_compound ,Eating ,Phosphatidylinositol 3-Kinases ,0302 clinical medicine ,Endocrinology ,Insulin ,Phosphorylation ,Neurotransmitter ,2. Zero hunger ,0303 health sciences ,biology ,Dexfenfluramine ,Postprandial Period ,Serotonin Receptor Agonists ,Liver ,[SDV.NEU]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC] ,medicine.drug ,medicine.medical_specialty ,Serotonin ,Hypothalamus ,03 medical and health sciences ,Insulin resistance ,Internal medicine ,Diabetes mellitus ,Cell Line, Tumor ,medicine ,Animals ,Humans ,Rats, Wistar ,Molecular Biology ,030304 developmental biology ,Receptor Cross-Talk ,medicine.disease ,Receptor, Insulin ,Rats ,Insulin receptor ,Disease Models, Animal ,chemistry ,Diabetes Mellitus, Type 2 ,biology.protein ,Proto-Oncogene Proteins c-akt ,030217 neurology & neurosurgery - Abstract
International audience; Serotonin and insulin are key regulators of homeostatic mechanisms in the hypothalamus. However, in type 2 diabetes, the hypothalamic responsiveness to serotonin is not clearly established. We used a diabetic model, the Goto Kakizaki (GK) rats, to explore insulin receptor expression, insulin and serotonin efficiency in the hypothalamus and liver by means of Akt phosphorylation. Insulin or dexfenfluramine (stimulator of serotonin) treatment induced Akt phosphorylation in Wistar rats but not in GK rats that exhibit down-regulated insulin receptor. Studies in a neuroblastoma cell line showed that serotonin-induced Akt phosphorylation is PI3-kinase dependent. Finally, in response to food intake, hypothalamic serotonin release was reduced in GK rats, indicating impaired responsiveness of this neurotransmitter. In conclusion, hypothalamic serotonin as insulin efficiency is impaired in diabetic GK rats. The insulin-serotonin cross-talk and impairment observed is one potential key modification in the brain during the onset of diabetes.
- Published
- 2012
29. Synthesis of Ether-linked Disaccharide and Trisaccharide Derivatives of the Type (3-5)-D-Xylan
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Jacques Yves Conan, Gino Ronco, Patrick Martin, Claude Rouch, Pierre Villa, Benali Harmouch, and Denis Postel
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chemistry.chemical_classification ,chemistry.chemical_compound ,Aldose ,Chemistry ,Stereochemistry ,One pot reaction ,Disaccharide ,Ether ,Alcohol ,General Chemistry ,Trisaccharide ,Xylan ,Toluene - Abstract
We have synthesized a series of non-glycosidically linked di- and trisaccharide monoethers of the type (3-5)-D-xylan, by a one-pot reaction between the alcohol ROH and 3,5-anhydro-l,2-O-isopropylidene-α-D-xylofuranose, in the presence of KOH and toluene-DMSO at 80 °C.
- Published
- 1994
30. Effects of insulin on brain monoamine metabolism in the zucker rat: Influence of genotype and age
- Author
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Y. Cohen, Christian Jacquot, Daniel Gripois, Marie-France Blouquit, Martine Orosco, Jacques Roffi, and Claude Rouch
- Subjects
Blood Glucose ,Serotonin ,medicine.medical_specialty ,Genotype ,Dopamine ,Endocrinology, Diabetes and Metabolism ,medicine.medical_treatment ,Hypothalamus ,Striatum ,Biology ,Eating ,Endocrinology ,Internal medicine ,Monoaminergic ,medicine ,Animals ,Insulin ,Biogenic Monoamines ,Obesity ,Biological Psychiatry ,Brain Chemistry ,Endocrine and Autonomic Systems ,Body Weight ,Dopaminergic ,Age Factors ,Tryptophan ,Brain ,Hydroxyindoleacetic Acid ,Corpus Striatum ,Rats ,Rats, Zucker ,Psychiatry and Mental health ,Monoamine neurotransmitter ,nervous system ,Basal (medicine) ,3,4-Dihydroxyphenylacetic Acid ,Female ,Insulin Resistance ,medicine.drug - Abstract
Disturbances of insulin or brain monoamine metabolism may play a role in the impaired regulation of food intake and body weight in the obese Zucker rat. We investigated a possible insulin-monoamine interaction by measuring monoamine levels in the hypothalamus and striatum of obese (fa-fa) and lean (Fa-Fa and Fa-fa) Zucker rats after peripheral insulin administration. The classically reported effects of insulin, i.e., increases in tryptophan, 5-hydroxy-indolacetic acid (5-HIAA) and dihydroxyphenylacetic acid (DOPAC) levels, were observed in the hypothalamus of Fa-Fa and Fa-fa rats, but not in obese fa-fa rats. Given the mechanism of action of insulin, this lack of effect in the obese rats may be related to the peripheral insulin resistance they exhibit. Furthermore, given the role of these monoaminergic systems, this reduced effect may be related to the impaired regulation of food intake and body weight. At 8 wk of age, however, insulin restored the decreased basal 5-HIAA levels observed in the obese rats. Increases in 5-HIAA levels following insulin administration appeared in the striatum of Fa-Fa rats only, suggesting that, as for brain insulin content, other central insulin-related disturbances may be related to the presence of the “fa” gene. In addition, certain effects of insulin on striatal dopamine release were observed in only the Fa-Fa and fa-fa rats, suggesting a particular disturbance related to the heterozygous character. This latter point calls for further investigations on the central dopaminergic effects of insulin.
- Published
- 1991
31. Reversal of a feeding-reward system by dexfenfluramine: Neurochemical involvement
- Author
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Y. Cohen, M. Orosco, J.J. Robert, Claude Rouch, and C. Jacquot
- Subjects
Serotonin ,medicine.medical_specialty ,Fenfluramine ,Dopamine ,Experimental and Cognitive Psychology ,Serotonergic ,Behavioral Neuroscience ,Neurochemical ,Internal medicine ,medicine ,Animals ,Hot plate test ,Appetitive Behavior ,Motivation ,beta-Endorphin ,Dopaminergic ,Brain ,Nociceptors ,Rats, Inbred Strains ,Feeding Behavior ,Dexfenfluramine ,Rats ,Endocrinology ,Sensory Thresholds ,Anorectic ,Female ,Psychology ,medicine.drug - Abstract
In addition to its anorectic properties, dexfenfluramine may inhibit some manifestations of feeding-related reward. We attempted to verify this effect by measuring paw-lick latency on the hot plate test in rats conditioned to expect a palatable food. The involvement of variations in β-endorphinergic, dopaminergic and serotonergic systems was assessed. Despite an inherent effect of increasing paw-lick latency, dexfenfluramine (1.5 mg/kg IP) partly reversed the expectancy-induced increase in this latency. Saline-treated “expectant” rats displayed elevated plasma β-endorphin levels and reduced hypothalamic 5-HIAA/5-HT and DOPAC/DA ratios. Only the decrease in the DOPAC/DA ratio was reversed by dexfenfluramine, suggesting an involvement of the dopaminergic system in this dexfenfluramine-sensitive reward system.
- Published
- 1990
32. Identification of endocannabinoids and related compounds in human fat cells
- Author
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Claude Rouch, Maya Cesari, Franck Festy, Marta Valenti, Marie-Paule Gonthier, Isabel Matias, Vincenzo Di Marzo, Serge Chesne, Sandrine Bes-Houtmann, Laurence Hoareau, Régis Roche, Christine Robert Da Silva, Christian Lefebvre d'Hellencourt, Diabète athérothrombose et thérapies Réunion Océan Indien (DéTROI), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de La Réunion (UR), and Université de La Réunion (UR)-Institut National de la Santé et de la Recherche Médicale (INSERM)
- Subjects
Adult ,medicine.medical_specialty ,Polyunsaturated Alkamides ,Endocrinology, Diabetes and Metabolism ,Medicine (miscellaneous) ,Adipokine ,Down-Regulation ,030209 endocrinology & metabolism ,Arachidonic Acids ,Glycerides ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Endocrinology ,Internal medicine ,Adipocyte ,Ciglitazone ,Cannabinoid Receptor Modulators ,medicine ,Adipocytes ,Humans ,Adiponectin secretion ,human ,Obesity ,adipokines ,030304 developmental biology ,0303 health sciences ,Nutrition and Dietetics ,Adiponectin ,peroxisome proliferator-activated receptor ,Chemistry ,Leptin ,Anandamide ,Middle Aged ,Endocannabinoid system ,Lipids ,3. Good health ,Up-Regulation ,PPAR gamma ,Adipose Tissue ,lipids (amino acids, peptides, and proteins) ,Female ,[SDV.MHEP]Life Sciences [q-bio]/Human health and pathology ,Endocannabinoids - Abstract
International audience; Objective: Recently, an activation of the endocannabinoid system during obesity has been reported. More particularly, it has been demonstrated that hypothalamic levels of both endocannabinoids, 2‐arachidonoylglycerol and anandamide (N‐arachidonoylethanolamine), are up‐regulated in genetically obese rodents. Circulating levels of both endocannabinoids were also shown to be higher in obese compared with lean women. Yet, the direct production of endocannabinoids by human adipocytes has never been demonstrated. Our aim was to evaluate the ability of human adipocytes to produce endocannabinoids.Research Methods and Procedures: The production of endocannabinoids by human adipocytes was investigated in a model of human white subcutaneous adipocytes in primary culture. The effects of leptin, adiponectin, and peroxisome proliferator‐activated receptor (PPAR)‐γ activation on endocannabinoid production by adipocytes were explored. Endocannabinoid levels were determined by high‐performance liquid chromatography (HPLC)‐atmospheric pressure chemical ionization (APCI)‐mass spectrometry (MS) analysis, leptin and adiponectin secretion measured by enzyme‐linked immunosorbent assay (ELISA), and PPAR‐γ protein expression examined by Western blotting.Results: We show that 2‐arachidonoylglycerol, anandamide, and both anandamide analogs, N‐palmitoylethanolamine and N‐oleylethanolamine, are produced by human white subcutaneous adipocytes in concentrations ranging from 0.042 ± 0.004 to 0.531 ± 0.048 pM/mg lipid extract. N‐palmitoylethanolamine is the most abundant cannabimimetic compound produced by human adipocytes, and its levels are significantly down‐regulated by leptin but not affected by adiponectin and PPAR‐γ agonist ciglitazone. N‐palmitoylethanolamine itself does not affect either leptin or adiponectin secretion or PPAR‐γ protein expression in adipocytes.Discussion: This study has led to the identification of human adipocytes as a new source of endocannabinoids and related compounds. The biological significance of these adipocyte cannabimimetic compounds and their potential implication in obesity should deserve further investigations.
- Published
- 2007
33. Persisting neural and endocrine modifications induced by a single fat meal
- Author
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Claude Rouch, Kyriaki Gerozissis, and Marie-Josée Meile
- Subjects
Blood Glucose ,Leptin ,Male ,medicine.medical_specialty ,Serotonin ,medicine.medical_treatment ,Microdialysis ,Hypothalamus ,Endocrine System ,Biology ,Serotonergic ,Cellular and Molecular Neuroscience ,Internal medicine ,medicine ,Glucose homeostasis ,Ingestion ,Animals ,Insulin ,Rats, Wistar ,Neurons ,Meal ,digestive, oral, and skin physiology ,Cell Biology ,General Medicine ,Postprandial Period ,Dietary Fats ,Rats ,Endocrinology ,Postprandial - Abstract
1. High-fat diets, modify the neuroendocrine response and, when prolonged, result in positive energy balance and obesity. Little is known about the effects of fat on the mechanisms operating in the initial steps of the neural and endocrine disturbances. 2. The studies reported here were designed to access the impact of the consumption of a single exclusively animal fat meal (lard), 24 h following its ingestion a) on the response of the hypothalamic serotonergic system to a standard laboratory chow meal and b) on the circulating levels of glucose, insulin, and leptin. The release of serotonin in the extracellular medial hypothalamic space (including the paraventricular-PVN and ventromedian-VMH nuclei) was determined using electrochemical detection following HPLC in samples obtained in vivo by microdialysis, in nonanesthetized adult male Wistar rats. 3. A lard meal resulted in decreased hypothalamic serotonin release postprandially and attenuated (24 h later) the hypothalamic serotonin response that normally follows a balanced meal. 4. In permanently catheterized rats, postprandial glucose and insulin levels measured in samples obtained in vivo, were either not, or only slightly, modified after a lard meal, whereas plasma leptin levels were increased. Interestingly, 24 h after a meal, insulin and leptin levels were increased in those animals eating a fat meal compared with those eating chow. Next-day glucose levels remained identical after the absorption either of a chow, or a lard meal. 5. The changes induced by the fat meal on peripheral and central regulators of energy and glucose homeostasis represent either adaptive mechanisms or early alterations that could render the organism vulnerable to further insults.
- Published
- 2005
34. Early changes in insulin secretion and action induced by high-fat diet are related to a decreased sympathetic tone
- Author
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Alain Ktorza, Christophe Magnan, M. Vincent-Lamon, M. Orosco, Claude Rouch, Céline Cruciani-Guglielmacci, Laboratoire de physiopathologie de la nutrition (LPN), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7), and Douared, Laetitia
- Subjects
Blood Glucose ,Male ,Nervous system ,medicine.medical_specialty ,Sympathetic nervous system ,Sympathetic Nervous System ,Physiology ,Endocrinology, Diabetes and Metabolism ,medicine.medical_treatment ,Oxymetazoline ,Hypothalamus ,030209 endocrinology & metabolism ,Biology ,Eating ,Norepinephrine ,03 medical and health sciences ,0302 clinical medicine ,Hyperinsulinism ,Physiology (medical) ,Internal medicine ,Insulin Secretion ,medicine ,Animals ,Insulin ,Secretion ,Rats, Wistar ,Sympathomimetics ,Insulin secretion ,Pancreatic hormone ,030304 developmental biology ,2. Zero hunger ,0303 health sciences ,Body Weight ,medicine.disease ,Dietary Fats ,Obesity ,Rats ,Autonomic nervous system ,Endocrinology ,medicine.anatomical_structure ,Liver ,Hyperglycemia - Abstract
To evaluate the relationship between the development of obesity, nervous system activity, and insulin secretion and action, we tested the effect of a 2-mo high-fat diet in rats (HF rats) on glucose tolerance, glucose-induced insulin secretion (GIIS), and glucose turnover rate compared with chow-fed rats (C rats). Moreover, we measured pancreatic and hepatic norepinephrine (NE) turnover, as assessment of sympathetic tone, and performed hypothalamic microdialysis to quantify extracellular NE turnover. Baseline plasma triglyceride, free fatty acid, insulin, and glucose concentrations were similar in both groups. After 2 days of diet, GIIS was elevated more in HF than in C rats, whereas plasma glucose time course was similar. There was a significant increase in basal pancreatic NE level of HF rats, and a twofold decrease in the fractional turnover constant was observed, indicating a change in sympathetic tone. In ventromedian hypothalamus of HF rats, the decrease in NE extracellular concentration after a glucose challenge was lower compared with C rats, suggesting changes in overall activity. After 7 days, insulin hypersecretion persisted, and glucose intolerance appeared. Later (2 mo), there was no longer insulin hypersecretion, whereas glucose intolerance worsened. At all times, HF rats also displayed hepatic insulin resistance. On day 2 of HF diet, GIIS returned to normal after treatment with oxymetazoline, an α2A-adrenoreceptor agonist, thus suggesting the involvement of a low sympathetic tone in insulin hypersecretion in response to glucose in HF rats. In conclusion, the HF diet rapidly results in an increased GIIS, at least in part related to a decreased sympathetic tone, which can be the first step of a cascade of events leading to impaired glucose homeostasis.
- Published
- 2005
35. Alpha-lactalbumin-enriched diets enhance serotonin release and induce anxiolytic and rewarding effects in the rat
- Author
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Valérie Daugé, Alain Regnault, Claude Rouch, Martine Orosco, Françoise Beslot, and Sebastien Feurté
- Subjects
Male ,medicine.medical_specialty ,Elevated plus maze ,Microdialysis ,Serotonin ,Sucrose ,Time Factors ,Hypothalamus ,Biology ,Anxiety ,Serotonergic ,Open field ,Behavioral Neuroscience ,Reward ,Casein ,Internal medicine ,medicine ,Ingestion ,Animals ,Rats, Wistar ,Maze Learning ,Meal ,Behavior, Animal ,digestive, oral, and skin physiology ,Caseins ,Diet ,Rats ,Endocrinology ,Anti-Anxiety Agents ,Exploratory Behavior ,Lactalbumin ,Conditioning, Operant ,Extracellular Space ,Locomotion - Abstract
Among food proteins, alpha-lactalbumin (LAC) has the highest ratio of tryptophan (Trp) over its competitor amino acids. Consequently, contrary to casein (CAS), LAC ingestion increases Trp access to the brain leading to enhanced serotonin (5-HT) synthesis. As an index of serotonergic activity, we assessed extracellular 5-HT in response to LAC ingestion, using microdialysis, and performed behavioural tests in rats in order to characterise the suggested improvements of mood observed in humans after ingestion of this protein. Rats were fed with diets enriched either in LAC or CAS as control, acutely (30 min meals) or chronically (3 and 6 days). A 30 min LAC meal significantly increased 5-HT release in the medial hypothalamus. This effect disappeared after 3 and 6 days of diet. The basal premeal 5-HT levels were increasingly enhanced by the LAC diet. Compared to a CAS meal, LAC increased the percentage of time spent on the open arms of the elevated plus maze and the number of visits to the centre of the open field, suggesting an anxiolytic-like effect. A single LAC meal decreased sucrose consumption, while 3 or 6 days diets enhanced it, reflecting an appetitive and/or rewarding action. In conclusion, LAC ingestion induces anxiolytic-like and rewarding effects possibly related to serotonergic activation. Shifting transiently, the commonly consumed CAS-enriched to LAC-enriched diets may induce beneficial effects on mood.
- Published
- 2003
36. Extracellular hypothalamic serotonin and plasma amino acids in response to sequential carbohydrate and protein meals
- Author
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Claude Rouch, M. Orosco, and M.J. Meile
- Subjects
Male ,medicine.medical_specialty ,Serotonin ,Hypothalamus ,Medicine (miscellaneous) ,Neurochemical ,Casein ,Internal medicine ,medicine ,Dietary Carbohydrates ,Ingestion ,Animals ,Amino Acids ,Rats, Wistar ,Meal ,Nutrition and Dietetics ,Chemistry ,General Neuroscience ,digestive, oral, and skin physiology ,Tryptophan ,Caseins ,General Medicine ,Carbohydrate ,Rats ,Kinetics ,Endocrinology ,Food ,Dietary Proteins ,Extracellular Space ,Blood sampling - Abstract
In previous studies, we showed that carbohydrate and protein ingestion, respectively, increased and decreased hypothalamic extracellular serotonin and the plasma ratio tryptophan over its competitor amino acids (Trp/LNAAs), reflecting serotonin synthesis. Serotonin levels returned towards baseline 2 h after either meal while the ratio remained altered. The question addressed is the ability of serotonin to respond expectedly to a second meal of the alternate nutrient. Rats were fed with sequential meals of either carbohydrates first and then casein 2 h later or in reverse order. Hypothalamic serotonin was measured using microdialysis. Permanent blood sampling allowed to track in parallel plasma amino acids. A carbohydrate meal increased hypothalamic serotonin, so did a subsequent casein meal. Conversely, following a casein meal that reduced serotonin, a carbohydrate meal also decreased it. The plasma ratio Trp/LNAAs was enhanced by a carbohydrate meal and remained high for 2h. A subsequent casein meal reversed this change but the ratio remained higher than basal values. A first casein meal reduced the ratio that was not increased again by a subsequent carbohydrate meal. It is obvious that ingestion of specific nutrients induce long-lasting metabolic and neurochemical variations that prevent subsequent changes to occur. The lack of expected changes to a second meal addresses again the hypothesis of alternate appetites for carbohydrates and proteins driven by serotonin changes.
- Published
- 2003
37. PO17 Rôle des céramides au niveau de l’hypothalamus dans la dérégulation de l’homéostasie glucidique durant l’installation de l’obésité
- Author
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H. Le Stunff, Claude Rouch, Mélanie Campana, Nadim Kassis, Christophe Magnan, Nicolas Coant, Erwann Philippe, and Stéphanie Migrenne
- Subjects
Endocrinology ,Endocrinology, Diabetes and Metabolism ,Internal Medicine ,General Medicine - Abstract
Introduction Des etudes recentes ont montre que l'accumulation de lipides dans l'hypothalamus serait responsable de l'installation d'une lipotoxicite centrale. Ce phenomene pourrait jouer un role dans l'apparition d'une insulinoresistance et du diabete en deregulant le controle nerveux de l'homeostasie glucidique. Il a ete montre que l'accumulation des ceramides joue un role preponderant dans le developpement d'une lipotoxicite au niveau des tissus peripheriques. Nos resultats preliminaires ont montre que la perfusion de saindoux, compose principalement d'acides gras satures, directement dans le cerveau, conduit a une insulino-resistance peripherique associee a une accumulation de ceramides dans l'hypothalamus. Materiels et methodes Afin etudier la chronologie qui existe entre l'installation d'une insulino-resistance centrale et peripherique, nous avons decide d'etudier les effets d'un acide gras sature, le palmitate sur l'insulino-resistance centrale a l'aide d'approches in vitro (cellules hypothalamiques) et in vivo (rat). Resultats Nous avons pu mettre en evidence un phenomene d'insulino-resistance centrale in vitro en reponse au palmitate qui s'accompagne d'une accumulation de ceramides. Certains ARNm codant pour les enzymes de la voie de synthese de novo des ceramides etant augmentes a la suite de ces traitements, nous avons decide d'inhiber cette voie avec la myriocine. En presence de myriocine, ce phenomene d'insulino-resistance centrale est partiellement contrecarre. Chez le rat, nous avons pu observer le meme phenomene d'insulino-resistance centrale en reponse a une perfusion dans la carotide de palmitate. Cette insulino-resistance s'accompagne a son tour d'une accumulation de ceramides dans l'hypothalamus. Conclusion Au final, notre etude revele que les acides gras satures induisent une accumulation de ceramides dans l'hypothalamus. De facon interessante, cette accumulation est responsable de l'installation d'une insulino-resistance hypothalamique. Ces resultats mettent en evidence le role cle du metabolisme des ceramides dans la deregulation du controle nerveux de l'homeostasie glucidique observe au cours de l'obesite.
- Published
- 2014
38. Rôle des céramides au niveau de l’hypothalamus dans la dérégulation de l’homéostasie glucidique durant l’installation de l’obésité
- Author
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H. Le Stunff, Mélanie Campana, Christophe Magnan, Nadim Kassis, Erwann Philippe, Claude Rouch, Stéphanie Migrenne, and Nicolas Coant
- Subjects
Nutrition and Dietetics ,Endocrinology, Diabetes and Metabolism ,Internal Medicine ,Medicine (miscellaneous) - Published
- 2013
39. Activation of hypothalamic insulin by serotonin is the primary event of the insulin-serotonin interaction involved in the control of feeding
- Author
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Martine Orosco, Kyriaki Gerozissis, and Claude Rouch
- Subjects
Blood Glucose ,Male ,medicine.medical_specialty ,Microdialysis ,Serotonin ,medicine.medical_treatment ,Dopamine ,Hypothalamus ,Biology ,Serotonergic ,chemistry.chemical_compound ,Norepinephrine ,Dexfenfluramine ,Internal medicine ,medicine ,Animals ,Insulin ,Rats, Wistar ,Neurotransmitter ,Molecular Biology ,Pancreatic hormone ,Appetite Regulation ,General Neuroscience ,Hydroxyindoleacetic Acid ,Insulin oscillation ,Rats ,Serotonin Receptor Agonists ,Endocrinology ,chemistry ,Ventromedial Hypothalamic Nucleus ,3,4-Dihydroxyphenylacetic Acid ,Neurology (clinical) ,Extracellular Space ,Developmental Biology ,medicine.drug ,Paraventricular Hypothalamic Nucleus - Abstract
In previous experiments, we reported a close parallelism in the responses of both serotonin (5-HT) and insulin in the hypothalamic PVN-VMH region of freely-moving rats during feeding. Thus, hypothalamic 5-HT and insulin may participate, independently or in interaction, in the control of carbohydrate and fat ingestion. The precedence of the activation of one or the other substance remained to be investigated. In adult male Wistar rats, (a) dexfenfluramine was administered to the PVN-VMH region by reverse microdialysis (80 microM for 10 min) while local insulin was assessed; (b) insulin was locally infused (400 mU for 10 min) through the tip of the dialysis probe while 5-HT was measured. Dexfenfluramine immediately increased 5-HT release, and also extracellular insulin levels (+102%). This activation of insulin by serotonin is actually a central effect since neither insulinemia nor glycemia were affected. Conversely, insulin enhanced 5-HT release (+81%), but only 45 min after the beginning of its infusion. Noradrenaline, dopamine and metabolites were slightly or not at all modified by insulin. These data demonstrate that an interaction does exist between insulin and 5-HT in the VMH-PVN area. Because of the delay of 5-HT response to insulin, an activation of the serotonergic system would be the causal event acting immediately on insulin, and not the contrary. Whatever the exact mechanism of this interaction, it seems to be a link in a larger cascade of events involving numerous neurotransmitters and peptides leading to the regulation of feeding.
- Published
- 2000
40. Inhibition of palmito polyphenoloxidase by halide salts
- Author
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Christine Robert, Frédéric Cadet, and Claude Rouch
- Subjects
Bromides ,Inorganic chemistry ,Iodide ,Halide ,Protonation ,Sodium Chloride ,Biochemistry ,Medicinal chemistry ,Chloride ,Binding, Competitive ,chemistry.chemical_compound ,Fluorides ,Chlorides ,Bromide ,medicine ,Enzyme Inhibitors ,chemistry.chemical_classification ,biology ,Active site ,Hydrogen-Ion Concentration ,Iodides ,biology.organism_classification ,chemistry ,biology.protein ,Molecular Medicine ,Sodium Fluoride ,Fluoride ,Acanthophoenix rubra ,Catechol Oxidase ,medicine.drug - Abstract
The inhibitory properties of halide salts on palmito polyphenoloxidase (PPO) are described. Halide salts have the same inhibitory effect on the two forms of palmito PPO separated by hydrophobic chromatography. Fluoride and chloride ions showed a non-competitive, mixed type inhibition while bromide and iodide ions were found to be non-competitive inhibitors. A study of the Ki for the different halide salts showed that the smaller F- ion is a stronger inhibitor than I- and Br- and that Cl- has the highest Ki value. This suggests that the active site of the palmito PPO is not easily accessible. The inhibition by chloride and fluoride ion was found to be pH-dependent. The inhibitory effects of these ions increased with a decrease in pH. It is suggested that halide ions (X) could bind to either the protonated enzyme (EH) or the protonated substrate-enzyme complex (EHS) to yield inactive forms EHX and EHSX, respectively.
- Published
- 1998
41. Contribution to the study of the Hatch and Slack photosynthetic cycle. Part I: Purification of a PEPcase-MDH-malic enzyme multienzymatic complex in a C4 plant (sugarcane)
- Author
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Pascal Baret, C. Queiroz, Claude Rouch, J. C. Meunier, and Frédéric Cadet
- Subjects
chemistry.chemical_classification ,Enzyme ,chemistry ,fungi ,Botany ,Malic enzyme ,food and beverages ,Biology ,Phosphoenolpyruvate carboxylase ,Photosynthesis - Abstract
We found out the existence in fresh young leaves of sugarcane of a PEPcase-MDH(NADP)-Malic enzyme multienzymatic complex. The enzyme was purified as follows
- Published
- 1998
42. Contribution to the study of the Hatch and Slack photosynthetic cycle. Part II: Kinetic properties of the PEPcase-MDH-Malic enzyme multienzymatic complex purified from a C4 plant (sugarcane)
- Author
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Frédéric Cadet, Claude Rouch, J. C. Meunier, C. Queiroz, and Pascal Baret
- Subjects
chemistry.chemical_classification ,Free state ,Enzyme ,chemistry ,Biochemistry ,Botany ,Malic enzyme ,Biology ,Phosphoenolpyruvate carboxylase ,Photosynthesis - Abstract
We found out the existence in fresh young leaves of sugarcane of a PEPcase-MDH(NADP)-Malic enzyme multienzymatic complex. We have been able to purify this complex. Its functional advantage has been investigated by comparing the kinetic properties of the constitutive enzymes in their free state with those in their complexed state.
- Published
- 1998
43. Fatty Acid Transporter CD36 Mediates Hypothalamic Effect of Fatty Acids on Food Intake in Rats
- Author
-
Christophe Guissard, Valentine S. Moullé, Julien Dairou, Christophe Magnan, Anne Lorsignol, Barry E. Levin, Claude Rouch, Linh-Chi Bui, Erwann Philippe, Céline Cruciani-Guglielmacci, Christelle Le Foll, Luc Pénicaud, Nadim Kassis, Nicolas Marsollier, Unité de Biologie Fonctionnelle et Adaptative (BFA (UMR_8251 / U1133)), Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7), Department of Neurology and Neurosciences, Rutgers New Jersey Medical School (NJMS), Rutgers University System (Rutgers)-Rutgers University System (Rutgers), STROMALab, Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Ecole Nationale Vétérinaire de Toulouse (ENVT), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Institut National de la Santé et de la Recherche Médicale (INSERM)-Etablissement Français du Sang-Centre National de la Recherche Scientifique (CNRS), Centre des Sciences du Goût et de l'Alimentation [Dijon] (CSGA), Institut National de la Recherche Agronomique (INRA)-Université de Bourgogne (UB)-AgroSup Dijon - Institut National Supérieur des Sciences Agronomiques, de l'Alimentation et de l'Environnement-Centre National de la Recherche Scientifique (CNRS), Funding: This work was supported in part by the Juvenile Diabetes Research Foundation (JDRF) (XF, VHR and AD) and the National Health Institute (VHR: 1RO1DK64566 and 1RO1DK81358, AB: 5RO1-GM067640, BO: 1F31DK86681). BO was also supported by the Alfred P. Sloan Foundation. AB was also supported by the F.M. Kirby Foundation. XF was also supported by the European Commission (PCIG-GA-2011-293738 NeuROSens). CL and LP were supported by the Agence Nationale de la Recherche (ANR-06-PHYSIO-Oox, 'Meta-DisMitoDyn')., Université Paris Diderot - Paris 7 (UPD7)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Vétérinaire de Toulouse (ENVT), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Etablissement Français du Sang-Institut National de la Santé et de la Recherche Médicale (INSERM), Institut National de la Recherche Agronomique (INRA)-Université de Bourgogne (UB)-Centre National de la Recherche Scientifique (CNRS), Julien, Sabine, Centre National de la Recherche Scientifique (CNRS)-AgroSup Dijon - Institut National Supérieur des Sciences Agronomiques, de l'Alimentation et de l'Environnement-Institut National de la Recherche Agronomique (INRA)-Université de Bourgogne (UB), Magnan, Christophe, Biologie Fonctionnelle et Adaptative ( BFA ), Université Paris Diderot - Paris 7 ( UPD7 ) -Centre National de la Recherche Scientifique ( CNRS ), NJ Medical School, STROMA Lab (UMR 5273), Université Paul Sabatier - Toulouse 3 ( UPS ) -Institut National de la Santé et de la Recherche Médicale ( INSERM ) -Centre National de la Recherche Scientifique ( CNRS ), Centre des Sciences du Goût et de l'Alimentation [Dijon] ( CSGA ), and Institut National de la Recherche Agronomique ( INRA ) -Université de Bourgogne ( UB ) -AgroSup Dijon - Institut National Supérieur des Sciences Agronomiques, de l'Alimentation et de l'Environnement-Centre National de la Recherche Scientifique ( CNRS )
- Subjects
CD36 Antigens ,Male ,Microdialysis ,medicine.medical_specialty ,[SDV.NEU.NB]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC]/Neurobiology ,CD36 ,Hypothalamus ,Gene Expression ,lcsh:Medicine ,Models, Biological ,Eating ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,In vivo ,Internal medicine ,medicine ,Animals ,lcsh:Science ,Phospholipids ,030304 developmental biology ,2. Zero hunger ,chemistry.chemical_classification ,0303 health sciences ,Multidisciplinary ,Triglyceride ,biology ,Fatty Acids ,lcsh:R ,Neurosciences ,[SDV.NEU.NB] Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC]/Neurobiology ,Fatty acid ,Feeding Behavior ,Fatty Acid Transport Proteins ,Rats ,Soybean Oil ,Triacsin C ,Endocrinology ,chemistry ,[ SDV.NEU.NB ] Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC]/Neurobiology ,Neurons and Cognition ,biology.protein ,Emulsions ,lcsh:Q ,Proto-Oncogene Proteins c-fos ,030217 neurology & neurosurgery ,Etomoxir ,Research Article - Abstract
Subject Areas: carotid arteries; emulsions; fatty acids; gene expression; heparin; hypothalamus; neurons; oxidation.; International audience; Variations in plasma fatty acid (FA) concentrations are detected by FA sensing neurons in specific brain areas such as the hypothalamus. These neurons play a physiological role in the control of food intake and the regulation of hepatic glucose production. Le Foll et al. previously showed in vitro that at least 50% of the FA sensing in ventromedial hypothalamic (VMH) neurons is attributable to the interaction of long chain FA with FA translocase/CD36 (CD36). The present work assessed whether in vivo effects of hypothalamic FA sensing might be partly mediated by CD36 or intracellular events such as acylCoA synthesis or β-oxidation. To that end, a catheter was implanted in the carotid artery toward the brain in male Wistar rats. After 1 wk recovery, animals were food-deprived for 5 h, then 10 min infusions of triglyceride emulsion, Intralipid +/- heparin (IL, ILH, respectively) or saline/heparin (SH) were carried out and food intake was assessed over the next 5 h. Experimental groups included: 1) Rats previously injected in ventromedian nucleus (VMN) with shRNA against CD36 or scrambled RNA; 2) Etomoxir (CPT1 inhibitor) or saline co-infused with ILH/SH; and 3) Triacsin C (acylCoA synthase inhibitor) or saline co-infused with ILH/SH. ILH significantly lowered food intake during refeeding compared to SH (p
- Published
- 2013
44. PO21 La délétion hippocampique de la LPL induit une intolérance au glucose associée à un défaut de sécrétion d’insuline chez la souris
- Author
-
Alexandre Picard, Claude Rouch, Céline Cruciani-Guglielmacci, Christophe Magnan, Nadim Kassis, and Serge Luquet
- Subjects
Endocrinology ,Endocrinology, Diabetes and Metabolism ,Internal Medicine ,lipids (amino acids, peptides, and proteins) ,General Medicine - Abstract
Introduction L’hippocampe participe au controle de la prise alimentaire, du poids corporel et des depenses energetiques. De plus, il est le site majeur d’activite et d’expression de la lipoproteine lipase (LPL), responsable de l’hydrolyse des triglycerides en acides gras libres. Nous formons l’hypothese que l’activite LPL hippocampique, via une modulation du lipid sensing cerebral, pourrait jouer un role dans le controle de la balance energetique. Materiels et methodes Des souris Lpl lox/lox ont ete croisees avec des souris exprimant la Cre recombinase sous promoteur CamK2α; (expression majoritaire dans la couche CA1 de l’hippocampe), l’absence de recombinaison au niveau des organes peripheriques tels que le pancreas a ete verifiee. La prise alimentaire, le poids, la composition corporelle et les depenses energetiques ont ete caracterisees chez la descendance. L’homeostasie glucidique a ete exploree par des tests de tolerance au glucose oral (OGTT) associes a la mesure de la secretion d’insuline, et des tests de tolerance a l’insuline (ITT). Resultats Les souris heterozygotes pour la deletion du gene Lpl presentent une diminution significative de l’activite LPL hippocampique et developpent un surpoids transitoire sans hyperphagie, associe a une augmentation de masse grasse et a une diminution des depenses energetiques, par rapport aux controles. Ces souris sont egalement intolerantes au glucose et presentent un defaut de secretion d’insuline en reponse au glucose. Elles sont en revanche plus sensibles a l’insuline. Les souris homozygotes ne presentent quant a elles pas de phenotype ni de diminution de l’activite LPL hippocampique. Conclusion La deletion heterozygote du gene Lpl sous promoteur Camk2α; induit une intolerance au glucose associee a un defaut de secretion d’insuline. Ces resultats sont en faveur d’un role de l’activite LPL hippocampique dans la regulation nerveuse de l’homeostasie glucidique.
- Published
- 2013
45. A kinetic study of the inhibition of palmito polyphenol oxidase by L-cysteine
- Author
-
Claude Rouch, Michel Pabion, Florence Richard-Forget, Frédéric Cadet, Christine Robert, ProdInra, Migration, Sécurité et Qualité des Produits d'Origine Végétale (SQPOV), and Avignon Université (AU)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)
- Subjects
Stereochemistry ,[SPI.GPROC] Engineering Sciences [physics]/Chemical and Process Engineering ,[SDV]Life Sciences [q-bio] ,01 natural sciences ,Biochemistry ,Polyphenol oxidase ,0404 agricultural biotechnology ,[SDV.IDA]Life Sciences [q-bio]/Food engineering ,Browning ,[SPI.GPROC]Engineering Sciences [physics]/Chemical and Process Engineering ,ComputingMilieux_MISCELLANEOUS ,chemistry.chemical_classification ,biology ,010401 analytical chemistry ,Substrate (chemistry) ,04 agricultural and veterinary sciences ,Cell Biology ,[SDV.IDA] Life Sciences [q-bio]/Food engineering ,040401 food science ,Enzyme assay ,0104 chemical sciences ,Quinone ,[SDV] Life Sciences [q-bio] ,Enzyme ,chemistry ,Thiol ,biology.protein ,Cysteine - Abstract
Polyphenol oxidase (PPO) is responsible for browning reactions in fruits and vegetables. In order to inhibit these reactions during processing, the use of chemical inhibitors including thiols such as L-cysteine has been proposed. The effect of this thiol on PPO activity was studied in order to establish if it reacts with quinone and/or directly inhibits the enzyme. The inhibition of palmito PPO (catecholase activity, with 4-methylcatechol as substrate) by L-cysteine was characterized spectrophotometrically. The effect of increasing cysteine concentration with respect to incubation time was measured by polarography and the kinetic parameters calculated. Kinetic analysis using spectrophotometric assays showed a lag period suggesting that there is no quinone accumulation in the reaction mixture. The increase of absorbance at 300 nm observed with u.v.—vis spectra indicated that a colourless compound (thiol—quinone complex) was produced. The plots of log remaining enzyme activity vs incubation time were characterized by two straight lines suggesting two possible inactivation models: (i) the deactivation of one enzyme that proceeds in two steps or (ii) the existence of two isoenzymes that behave differently. We have shown that the inactivation process of PPO by cysteine followed this model: N → X[C] → I where N represents one native form, X represents an intermediate form, the structure of which depends on the cysteine concentration [C], and where I is the completely inactive form of the enzyme. These results showed that there is a direct irreversible inhibition of PPO by cysteine according to a two-step model. The analytical approach illustrated by the present study of palmito PPO inhibition by L-cysteine may be applied to other investigations of mechanisms of enzyme inhibition.
- Published
- 1996
46. Enzyme kinetics by mid-infrared spectroscopy: beta-fructosidase study by a one-step assay
- Author
-
Christine Robert, Françoise Wong Pin, Pascal Baret, Claude Rouch, and Frédéric Cadet
- Subjects
Sucrose ,medicine.diagnostic_test ,Glycoside Hydrolases ,Spectrophotometry, Infrared ,beta-Fructofuranosidase ,Chemistry ,Kinetics ,Biophysics ,Analytical chemistry ,Substrate (chemistry) ,One-Step ,Disaccharides ,Biochemistry ,Structural Biology ,Attenuated total reflection ,Spectrophotometry ,Calibration ,medicine ,Principal component regression ,Enzyme kinetics ,Molecular Biology - Abstract
An alternate method for enzyme study is proposed. Multidimensional statistical analysis applied on mid-infrared attenuated total reflectance spectra (Cadet et al. (1991) Appl. Spectrosc. 42, 166-172) collected during a kinetic allows a direct and fast quantification of the remaining substrate, as well as a one step enzymatic assay. Furthermore, the combination of these techniques may be used as a structural tool. The method applied to the study of beta-fructosidase is developed in this paper as an example. With appropriate calibration, the method may be extend to any enzyme.
- Published
- 1995
47. A PEPc/MDH enzymatic complex in sugar cane (C4 plant)
- Author
-
Pascal Baret, Claude Rouch, Jean-Claude Meunier, and Frédéric Cadet
- Published
- 1995
48. 031 L’inhibition intra-hippocampique de la lipoprotéine lipase chez le rat entraine une augmentation du poids sans modifier la prise alimentaire
- Author
-
Claude Rouch, K. Davies, Christophe Magnan, Deborah J. Clegg, Céline Cruciani-Guglielmacci, and A. Picard
- Subjects
Endocrinology ,Endocrinology, Diabetes and Metabolism ,Internal Medicine ,General Medicine - Abstract
Introduction Le controle de la balance energetique implique des signaux peripheriques (hormones, nutriments) qui transmettent des informations aux structures specialisees du cerveau. Il a ete montre que l’hippocampe jouait un role dans le controle de la prise alimentaire. De plus, l’hippocampe est le site nerveux majeur d’expression de la lipoproteine lipase (Lpl). Dans le cadre d’un lipid sensing cerebral, nous formulons l’hypothese que l’hydrolyse des TG par la Lpl hippocampique joue un role dans le controle de l’equilibre energetique via la liberation locale d’AGL. Materiels et methodes Des mini-pompes osmotiques ont ete inserees par stereotaxie dans l’hippocampe de rats Wistar. Ils ont recu soit du NaCl 0.9 % (SAL) soit du tyloxapol (inhibiteur de la Lpl), a la dose de 10 µg/jour (TYL) pendant 28 jours. La prise alimentaire et le poids ont ete releves quotidiennement, et la composition corporelle de facon hebdomadaire. A j28, de nombreux parametres plasmatiques et tissulaires ont ete quantifies. Resultats Apres 28 jours de perfusion de tyloxapol, l’activite Lpl a diminue de 26 % dans l’hippocampe (p Conclusion L’inhibition de la Lpl hippocampique par une perfusion chronique de Tyloxapol conduit a une prise de poids due majoritairement a une augmentation de masse grasse accompagnee d’une diminution de la taille des adipocytes. La prise alimentaire, les TG et AGL plasmatiques ne sont pas modifies. De plus, les rats TYL presentent une hyperinsulinemie sans modification de la glycemie. Ces resultats suggerent que l’activite Lpl hippocampique peut influencer le controle nerveux de la balance energetique.
- Published
- 2011
49. Fasting affects more markedly neuropeptide Y than monoamines in the rat brain
- Author
-
C. Bohuon, M. Orosco, C. Jacquot, N. Pages, O. Yao, and Claude Rouch
- Subjects
Male ,medicine.medical_specialty ,Serotonin ,Clinical Biochemistry ,Hippocampus ,Striatum ,Toxicology ,Biochemistry ,Rats, Sprague-Dawley ,Behavioral Neuroscience ,Internal medicine ,Cortex (anatomy) ,mental disorders ,medicine ,Animals ,Biogenic Monoamines ,Neuropeptide Y ,Biological Psychiatry ,Pharmacology ,Brain Chemistry ,Chemistry ,Dopaminergic ,Fasting ,Hydroxyindoleacetic Acid ,Neuropeptide Y receptor ,humanities ,Rats ,Monoamine neurotransmitter ,medicine.anatomical_structure ,Endocrinology ,nervous system ,Catecholamine ,medicine.drug - Abstract
Monoamine turnover and neuropeptide Y (NPY) levels were evaluated in the CNS of 48- and 72-h-fasting adult, male rats in four brain areas: the hypothalamus, cortex, hippocampus, and striatum. In 48-h-fasted rats, NPY levels increased in the cortex and decreased in the striatum. The dopaminergic turnover increased in the hippocampus. The serotonergic turnover decreased in the hippocampus, striatum, and cortex and was still decreased after 72 h of fasting. In 72-h-fasted rats, an overall significant increase of NPY levels was observed except in the striatum, where it decreased significantly. No relationshp appeared between NPY and monoamine levels, suggesting that NPY can act independently in feeding behavior and play, in different brain areas, an important role in its regulation.
- Published
- 1993
50. Striatal dopamine metabolism is differentially affected by insulin according to the genotype in Zucker rats: a microdialysis study
- Author
-
Daniel Gripois, Claude Rouch, Yves Cohen, Christian Jacquot, Marie-France Blouquit, Jacques Roffi, and M. Orosco
- Subjects
medicine.medical_specialty ,Microdialysis ,Genotype ,Endocrinology, Diabetes and Metabolism ,medicine.medical_treatment ,Dopamine ,Biology ,5-Methoxytryptamine ,chemistry.chemical_compound ,Eating ,Endocrinology ,Internal medicine ,medicine ,Animals ,Insulin ,Biological Psychiatry ,Pancreatic hormone ,Endocrine and Autonomic Systems ,Homovanillic acid ,Dopaminergic ,Body Weight ,Homovanillic Acid ,Corpus Striatum ,Rats ,Rats, Zucker ,Psychiatry and Mental health ,Monoamine neurotransmitter ,chemistry ,Catecholamine ,3,4-Dihydroxyphenylacetic Acid ,Female ,medicine.drug - Abstract
The genetically obese Zucker rat presents several abnormalities related to insulin and brain monoamines, which may play a role in its impaired regulation of food intake and body weight. In a previous study, the possible insulin-monoamine interplay was investigated by measuring brain monoamine and metabolite levels in the three genotypes of the Zucker strain. In addition to the expected results, insulin had a particular effect on striatal dopamine (DA) release, regardless of ponderal status and genotype. We further investigated this point in the present study, using the brain microdialysis technique in the striatum. Lean homozygous Fa-Fa rats responded as expected to insulin with regard to striatal DA release, with increases in DA and 3-methoxy-tyramine levels and decreases in dihydroxyphenylacetic acid and homovanillic acid. Lean heterozygous Fa-fa rats showed a very specific response profile, with decreases in all dopaminergic parameters, suggestive of an effect on DA synthesis rather than DA release. This further emphasizes the marked differences between homozygous and heterozygous lean rats. The obese fa-fa rats clearly fell into two populations. The first showed a profile of response to insulin similar to that of the lean Fa-fa rats, in keeping with the disturbances related to the “fa” gene. The second showed an increase in all the dopaminergic parameters. This pattern of response was, however, different from that of the Fa-Fa rats. These opposing responses in the two obese populations did not reflect differences in the blood glucose response to insulin. One explanation is that 16 wk may be a critical transition period in the development of genetic obesity, with regard to brain monoamine disturbances and the response to insulin.
- Published
- 1992
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