Introduction: Oxidative stress can promote the development of complications of diabetes. Moderate exercise improves cardiac antioxidant status in diabetic animals. The current study aimed to investigate the effect of 8 week endurance exercise training on some heart antioxidant enzyme activities and lipid peroxidation of heart tissue in streptozotocin-induced diabetic rats.
Methods: To this end, 30 male Wistar rats were randomly divided into 3 groups: the healthy control group (C), diabetic control group (DC) and trained diabetic group (TD). Animals in TD group were exercised on a treadmill 4 days a week for 8 weeks. After 8 weeks, superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (CAT) activities and malondialdehyde (MDA) levels were measured in heart tissues. The data were analyzed using one-way ANOVA (p<0.05).
Results: The CAT and GPx activities of the heart tissue in DC group were found to be significantly higher (p=0.000) in compared with C group, whereas SOD activity was not found significantly different among the experimental groups. Also, heart GPx activity in TD group was significantly lower (p=0.000) than that of DC group, while CAT activity was not affected by endurance training. After 8-week endurance exercise (TD group), the MDA levels of heart tissue were significantly higher (respectively p<0.017 and p=0.000) than C and DC groups.
Conclusion: The results of the present study have demonstrated that due to decreased GPx activities and MDA levels, endurance exercise may make the heart tissue more susceptible to oxidative stress.