title: Swim training restores glucagon-like peptide-1 insulinotropic action in pancreatic islets from monosodium glutamate-obese rats.
abstract: OBJECTIVE
  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-1 immunoreactivity 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.
authors.affiliation: Department of Structural Biology, Molecular and Genetic, State University of Ponta Grossa, Ponta Grossa, PR, Brazil.
authors.forename: P V
authors.initials: PV
authors.lastname: Svidnicki
authors.forename: N
authors.initials: N
authors.lastname: de Carvalho Leite
authors.forename: A C
authors.initials: AC
authors.lastname: Venturelli
authors.forename: R L
authors.initials: RL
authors.lastname: Camargo
authors.forename: M R
authors.initials: MR
authors.lastname: Vicari
authors.forename: M C
authors.initials: MC
authors.lastname: de Almeida
authors.forename: R F
authors.initials: RF
authors.lastname: Artoni
authors.forename: V
authors.initials: V
authors.lastname: Nogaroto
authors.forename: S
authors.initials: S
authors.lastname: Grassiolli
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D052216:Glucagon-Like Peptide 1 / Q000378:metabolism* / Q000494:pharmacology; D005947:Glucose / Q000378:metabolism; D007328:Insulin / Q000378:metabolism; D007515:Islets of Langerhans / Q000187:drug effects; D009765:Obesity / Q000378:metabolism*; D010805:Physical Conditioning, Animal / Q000502:physiology*; D017208:Rats, Wistar; D012970:Sodium Glutamate / Q000378:metabolism*; D013550:Swimming / Q000502:physiology*
chemical_list: D007328:Insulin; D052216:Glucagon-Like Peptide 1; D005947:Glucose; D012970:Sodium Glutamate
keywords: exercise; insulin secretion; obesity