title: Physical exercise introduced after weaning enhances pancreatic islet responsiveness to glucose and potentiating agents in adult MSG-obese rats.
abstract: Physical exercise represents an alternative way to prevent and/or ameliorate chronic metabolic diseases. Disruption of sympathetic nervous system (SNS) activity contributes to adiposity in obese subjects. Here, we verified the preventive effect of swimming training upon adiposity, adrenal catecholamine storage, and pancreatic islet function in obese monosodium glutamate (MSG)-treated rats. Male neonatal Wistar rats received MSG (4 mg/g body weight) during the first 5 days of life and, at weaning, half of the rats were submitted to swimming training, 30 min/day, 3 days a week, until 90 days of age (exercised rats: MSGex). Half of the rats were used as controls (sedentary group, MSGsd). Exercise training (ET) decreased insulinemia and fat deposition in MSGex, and increased adrenal catecholamine content, compared with MSGsd rats. Insulinemia during the ivGTT was lower in MSGex rats, despite a lack of difference in glycemia. Swimming training enhanced insulin release in islets challenged by 2.8-8.3 mmol/l glucose, whereas, at supraphysiological glucose concentrations (11.1-16.7 mmol/l), MSGex islets secreted less insulin than MSGsd. No differences in insulin secretion were observed following l-arginine (Arg) or K(+) stimuli. In contrast, islets from MSGex rats secreted more insulin when exposed to carbachol (100 μmol/l), forskolin (10 μmol/l), or IBMX (1 mmol/l) at 8.3 mmol/l glucose. Additionally, MSGex islets presented a better epinephrine inhibition upon insulin release. These results demonstrate that ET prevented the onset of obesity in MSG rats, probably by enhancing adrenal catecholamine levels. ET ameliorates islet responsiveness to several compounds, as well as insulin peripheral action.
authors.affiliation: Universidade Federal do Rio de Janeiro (UFRJ), Campus UFRJ-Macaé, Macaé, RJ, Brazil.
authors.forename: R A
authors.initials: RA
authors.lastname: Ribeiro
authors.affiliation: Laboratório de Fisiologia Endócrina e Metabolismo, Centro de -Ciências -Biológicas e da Saúde, Universidade Estadual do Oeste do Paraná -(UNIOESTE), Cascavel, PR, Brazil.
authors.forename: M L
authors.initials: ML
authors.lastname: Bonfleur
authors.affiliation: Laboratório de Pâncreas Endócrino e Metabolismo, Departamento de -Biologia Estrutural e Funcional, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), Campinas, SP, Brazil.
authors.forename: E C
authors.initials: EC
authors.lastname: Vanzela
authors.affiliation: Laboratório de Fisiologia Endócrina e Metabolismo, Centro de -Ciências -Biológicas e da Saúde, Universidade Estadual do Oeste do Paraná -(UNIOESTE), Cascavel, PR, Brazil.
authors.forename: A I
authors.initials: AI
authors.lastname: Zotti
authors.affiliation: Laboratório de Biologia Celular da Secreção, Departamento de Biologia Celular e Genética, Universidade Estadual de Maringá (UEM), Maringá, PR, Brazil.
authors.forename: D X
authors.initials: DX
authors.lastname: Scomparin
authors.affiliation: Laboratório de Pâncreas Endócrino e Metabolismo, Departamento de -Biologia Estrutural e Funcional, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), Campinas, SP, Brazil.
authors.forename: A C
authors.initials: AC
authors.lastname: Boschero
authors.affiliation: Laboratório de Fisiologia Endócrina e Metabolismo, Centro de -Ciências -Biológicas e da Saúde, Universidade Estadual do Oeste do Paraná -(UNIOESTE), Cascavel, PR, Brazil.
authors.forename: S L
authors.initials: SL
authors.lastname: Balbo
mesh_terms: D000818:Animals; D015444:Exercise; D005081:Exercise Therapy; D005947:Glucose / Q000378:metabolism*; D006801:Humans; D007328:Insulin / Q000378:metabolism; D000078790:Insulin Secretion; D007515:Islets of Langerhans / Q000378:metabolism*; D008297:Male; D009765:Obesity / Q000378:metabolism* / Q000503:physiopathology / Q000628:therapy*; D051381:Rats; D017208:Rats, Wistar; D012970:Sodium Glutamate / Q000009:adverse effects* / Q000378:metabolism; D013550:Swimming; D014886:Weaning
chemical_list: D007328:Insulin; D005947:Glucose; D012970:Sodium Glutamate