The effect of resistance exercise on oxidative stress in cardiac and skeletal muscle tissues of streptozotocin-induced diabetic rats

Background and Objective: It has been shown that oxidative stress increases in diabetes and it has an important role in its development and subsequent complications. Thus, the aim of this study was to investigate the effect of acute resistance exercise on oxidative stress in skeletal muscle and cardiac tissues of streptozotocin-induced diabetic rats. Materials and Methods: Twenty male wistar rats were rendered diabetic by a single dose of streptozotocin (STZ; 50 mg/kg, IP) and were randomly divided into two groups: (1) acute resistance exercise and (2) sedentary control. Acute resistance exercise consisted of 4 separate sessions of exercise that happened in non-consecutive days. After the last session, the animals were anesthetized by xylazine (10 mg/kg) and ketamine (75 mg/kg) and flexor hallucis longus (FHL) muscle and heart were surgically removed and stored at -80 °C until biochemical analysis of malondialdehyde (MDA), protein carbonyl (PC), and glutathione (GSH) was done. Results: Our findings showed a significant decrease of MDA (p=0.007), but not PC level (p=0.678) of cardiac tissue of resistance exercise group. However, in FHL muscle, resistance exercise caused a significant increase in MDA (p=0.01), but there was no significant changes in PC level (p=0.399). Resistance exercise also caused a small but insignificant increase in GSH content of both skeletal and cardiac muscle tissues (p=0.11 and p=0.19, respectively). Conclusion: We observed that in diabetic rats, acute resistance exercise decreases cardiac tissue MDA, increases skeletal muscle MDA level, and had no significant effect on PC and GSH level. Further research is needed to specify the mechanisms of these differences in various tissues following resistance exercise.