Effects of aerobic exercise on Nrf2-SOD pathway in the gastrocnemius of rats with high-glucose and high-fat diet

Abstract

Objective: To investigate the changes of nuclear factor erythroid 2-related factor 2 (Nrf2) and superoxide dismutase (SOD) in the prevention of insulin resistance in skeletal muscle of rats by aerobic exercise. Methods: Twenty-four 12-month old Sprague-Dawley (SD) rats were randomly divided into control (C), insulin resistance model (IR) and insulin resistance model and exercise (IRE) groups. IR was induced by high- glucose and high-fat diet. Rats of IRE received the increasing load running on the treadmill for 6 W. The activity of total superoxide dismutase (T-SOD), catalase (CAT), Malonaldehyde (MDA) and glutathione / L-glutathione oxidized (GSH/GSSG) were measured by experiment kits. The content of 8-hydroxy-2 deoxyguanosine (8-OHdG) was measured by ELISA Kits. The expressions of Nrf2 and Glucose transporters 4 (GLUT4) in gastrocnemius were detected by Western Blot. Results: ①Compared with IR, the content of HOMA-IR was decreased in IRE (P＜0.05), while the content of muscle glycogen was increased in IRE (P＜0.01). ② The activities of T-SOD, CAT, and GSH/GSSG in IRE were significantly increased compared with those in IR (P＜0.01). Compared with IR, the contents of 8-OHdG and MDA in IRE were significantly decreased (P＜0.01). ③ The expressions of Nrf2 and GLUT4 in gastrocnemius of IRE rats were increased than those in IR (P＜0.01). Conclusion: The Nrf2 pathway was activated in gastrocnemius of rats after aerobic exercise, which promoted the activity of antioxidant enzymes, and prevented IR induced by high- glucose and high-fat diet.