Aerobic swimming training increases the activity of antioxidant enzymes and the glycogen content in the skeletal muscle of rats

Abstract

Introduction: Studies which verified the effects of physical exercise on oxidative stress biomarkers and its relation to muscle glycogen are scant. Objective: The present study verified the effects of aerobic swimming training (AST) on biomarkers of oxidative stress, glycogen content and cell growth in the skeletal muscle of rats. Methods: Eighteen male Wistar rats (60 days) were divided into two groups: Sedentary Group (SG; n = 10): sedentary rats; and Trained Group (TG; n = 8): rats subjected to AST (5.0% of body weight), 1h/day, 5x/week, during 8 weeks. The activity of antioxidant enzymes (AOE) superoxide dismutase (SOD; U/ml), catalase (CAT; μmol/min/100mg), glutathione peroxidase (GPx; nmol/min/100mg), and substances that react with thiobarbituric acid levels (TBARs; nmolMDA/ mg protein) were determined in the right gastrocnemius muscle. Glycogen (mg/100mg), protein (g/100g), and DNA (g/100g) contents were evaluated in the left gastrocnemius muscle. Data were analyzed by Student t-test (p < 0.05). Results: AOE activity was higher in the TG group (CAT: 0.87 ± 0.04; SOD: 6.49 ± 0.45; GPX: 6.49 ± 0.52) when compared to SG group (CAT: 0.52 ± 0.03; SOD: 4.10 ± 0.37; GPx: 2.87 ± 0.35). TBARs levels was lower in TG (TG: 2.35 ± 0.45; SG: 8.90 ± 0.47). Gastrocnemius glycogen content (SG: 0.108 ± 0.013; TG: 0.320 ± 0.012) and protein/DNA ratio (SG: 24.94 ± 3.25; TG: 41.68 ± 4.02) were higher in TG group. Conclusion: Altogether, these data provide evidence that AST improved antioxidant defense, which may be associated to higher glycogen content of skeletal muscle of the animals.