The incidence of insulin resistance increases with age. This work tested the effect of exercise on age- induced insulin resistance and the possible involved mechanisms. Six groups of rats were used: 4 months old, 14 months old and 24 months old, either with and without exercise training. Swimming exercise training was performed 2h/day, 5days/week for 6 weeks. Insulin resistance was assessed by measuring serum glucose, serum insulin and homeostasis model assessment of insulin resistance (HOMA-IR) index. Serum levels of catecholamines, inflammatory cytokines and total antioxidant capacity (TAC) together with skeletal muscle Glut4 mRNA expression were assessed. Aged rats developed insulin resistance associated with increased serum catecholamines and inflammatory cytokine levels, decreased serum TAC and suppression of skeletal muscle Glut4 expressions. Exercise training reversed the developed insulin resistance and restored the values of catecholamines, inflammatory cytokines and skeletal muscle Glut4; however, it did not modify TAC. It was concluded that exercise could reverse aging-induced insulin resistance in rats by decreasing catecholamines and inflammatory cytokines production and also by increasing Glut4 expression in skeletal muscles. |
