Swim training restores glucagon-like peptide-1 insulinotropic action in pancreatic islets from monosodium glutamate-obese rats

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Aims: Glucagon-like peptide-1 (GLP-1) is an important modulator of insulin secretion by endocrine pancreas. In the present study, we investigated the effect of swim training on GLP-1 insulinotropic action in pancreatic islets from monosodium glutamate (MSG)-obese rats. Methods: Obesity was induced by neonatal MSG administration. MSG-obese and control (CON) exercised rats swam for 30 min (3 times week(-1)) for 10 weeks. Pancreatic islets were isolated by colagenase technique and incubated with low (5.6 mM) or high (16.7 mM) glucose concentrations in the presence or absence of GLP-1 (10 nM). In addition, GLP-1 gene expression in ileum was quantified in fasting and glucose conditions. Results: Exercise reduced obesity and hyperinsulinemia in MSG-obese rats. Swim training also inhibited glucose-induced insulin secretion in islets from both groups. Islets from MSG-obese rats maintained GLP-1 insulinotropic response in low glucose concentration. In contrast, in the presence of high glucose concentration, GLP-1 insulinotropic action was absent in islets from MSG-obese rats. Islets from MSG-exercised rats showed reduced GLP-1 insulinotropic action in the presence of low glucose. However, in high glucose concentration swim training restored GLP-1 insulinotropic response in islets from MSG-obese rats. In all groups, glucose intake increased GLP-1immunoreactivity and gene expression in ileum cells in relation to fasting conditions. Swim training reduced these parameters only in ileum cells from CON-exercised rats. Neither MSG treatment nor exercise affected GLP-1 expression in the ileum. Conclusions: Exercise avoids insulin hypersecretion restoring GLP-1's insulinotropic action in pancreatic islets from MSG-obese rats.20913444Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundacao Araucaria (Fundacao Araucaria de Apoio ao Desenvolvimento Cientifico e Tecnologico do Estado do Parana)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)SETI/UGF (Secretaria de Estado da Ciencia, Tecnologia e Ensino Superior/Unidade Gestora do Fundo do Parana)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq