The effects of aerobic exercise training on oxidative stress and uitrastructure of pancreas tissue in diabetic rats

Abstract

Objective To investigate the effects of aerobic exercise training on oxidative stress and ultrastructure of pancreas tissue in diabetic rats and the mechanism of protective effects of aerobic exercise training on pancreatic mitochondria in diabetic rats. Methods Thirty Sprague-Dawley rats were randomly divided into three groups:a normal control group,a diabetic model group and an exercise diabetic group,with 10 rats in each group.Type 2 diabetic rat models were established by intra-abdominal injection of streptozotocin (STZ).The success rate of establishing diabetic rat models was 85.7％.The normal control group and diabetic model group were not given exercise training.Exercise group was trained with 8 weeks of swimming of medium strength,eg.60 min/time,5 d/week. After training for 8 weeks, the activities of superoxide dismutase (SOD), glutathion peroxidase (GPX),nitric oxide synthase (NOS) and the contents of malondialdehyde (MDA) and nitric oxide (NO) in pancreatic mitochondria were observed respectively.The ultrastructures of pancreas tissue in rats were observed under electron microscope. Results After swimming training for 8 weeks,the activities of SOD and GPx in pancreatic mitochondria in exercise diabetic group elevated more obviously than those in diabetic model group ( P ＜ 0.05 ),while the activity of NOS and the contents of MDA and NO reduced obviously (P ＜ 0.05 ).Compared with diabetic model group,the ultrastructures of pancreas tissue in exercise diabetic group improved,and the histomorphology was similar to normal control group. Conclusions Aerobic exercise training can provide protective effects on pancreas in diabetic rats,and can enhance antioxidation ability to eliminate free radicals,improve the ultrastructures of pancreas tissue. Key words: Aerobic exercise; Diabetes mellitus; Pancreas; Oxidative stress; Ultrastructure