Exercise improved rat metabolism by raising PPAR-α

Abstract

Based on the importance of exercise and crucial role of liver in metabolism, the aim of this study was to determine whether the expression of peroxisome proliferator-activated receptor (PPAR)-, and adiponectin receptor 2 in OLETF rat liver were altered in conjunction with improved metabolism with exercise training. OLETF rats were randomly assigned to 2 groups: sedentary control group (n=26), and long-term exercise-trained group (n=26). Full data were available on 32 OLETF rats (16 for each group). Adiponectin, glucose, insulin, triglyceride and cholesterol were assessed. Livers were taken to determine the expression of PPAR-, and adiponectin receptor 2. Compared with sedentary control group, fasting glucose (9.38±2.99mmol/L vs. 7.32±1.76mmol/L, P<0.05), triglyceride (1.73±0.34mmol/L vs. 0.89±0.12mmol/L, P<0.05) and cholesterol (4.41±0.75mmol/L vs. 2.13±0.32mmol/L, P<0.05) were substantially reduced after exercise, which significantly correlated with increased PPAR- (P<0.05) in liver. The expression of PPAR- upstream and target genes, including hepatocyte nuclear factor-4 (HNF4), carnitine palmitoyl transferase 1 (CPT-1), catalase (CAT) and ATPbinding cassette transporter A1 (ABCA1) also increased significantly. Therefore, our findings suggest that increased PPAR- expression in OLETF rats liver is a contributory factor to the exercise-related improvements in whole-body metabolism. © Georg Thieme Verlag KG Stuttgart - New York.