Moderate exercise restores pancreatic beta-cell function and autonomic nervous system activity in obese rats induced by high-fat diet.
OBJECTIVE
Metabolic syndrome has been identified as one of the most significant threats to human health in the 21(st) century. Exercise training has been shown to counteract obesity and metabolic syndrome. The present study aimed to investigate the effects of moderate exercise training on pancreatic beta-cell function and autonomic nervous system (ANS) activity in rats fed a high-fat diet (HFD).


METHODS
Weaning rats were divided into four groups: rats fed a standard chow or HFD (sedentary, Control-SED and HFD-SED; or exercised, Control-EXE and HFD-EXE, respectively). Exercised rats ran (from 21- to 91-days-old) for 60 minutes (3 times/week) over a 10-week period. Glucose and insulin tolerance tests were performed. Pancreatic islets were isolated to study glucose-induced insulin secretion (GIIS). Parasympathetic and sympathetic nerve electrical signals were measured, and liver samples were processed and histologically analyzed.


RESULTS
Exercise prevented obesity, insulin resistance, and liver steatosis as well as improved total cholesterol, ALT, and AST levels. Islets from HFD rats showed insulin hypersecretion which was ameliorated by exercise. Exercise decreased vagal nerve activity in the HFD-EXE group and increased the activity of the sympathetic nervous system in both exercised groups.


CONCLUSIONS
Exercise prevents obesity and liver steatosis and restores pancreatic beta-cell function and ANS activity in HFD-obese rats.
Department of Cell Biology and Genetic, State University of Maringá, Maringá PR Brazil.
Rodrigo Mello
RM
Gomes
Laize Peron
LP
Tófolo
Wilson
W
Rinaldi
Dionizia Xavier
DX
Scomparin
Sabrina
S
Grassiolli
Luiz Felipe
LF
Barella
Júlio Cezar
JC
de Oliveira
Renato Chaves Souto
RC
Branco
Aryane Rodrigues
AR
Agostinho
Tatiane Aparecida da Silva
TA
Ribeiro
Clarice
C
Gravena
Paulo Cezar de Freitas
PC
Mathias
D000818:Animals; D001341:Autonomic Nervous System / Q000378:metabolism*; D002478:Cells, Cultured; D059305:Diet, High-Fat; D050417:Insulin-Secreting Cells / Q000378:metabolism*; D008297:Male; D009765:Obesity / Q000503:physiopathology / Q000628:therapy; D010805:Physical Conditioning, Animal; D051381:Rats; D017208:Rats, Wistar