Oxidative stress in rats exercised at different intensities

Abstract

Objective: The present study aimed to analyze the effects of physical training at different intensities on aerobic conditioning and oxidative stress biomarkers in rats. Methods: Wistar rats (90 d of age) weighing 250 ∼320 g at the beginning of the experiment had the aerobic/anaerobic metabolic transition determined by maximal lactate steady state test (MLSS). The rats were trained during 40 min/d, 5 d/week, at the speed equivalent to MLSS (MT) or 25% above it (AT), during 8 weeks. As controls, rats maintained sedentary (S) were used. At the end, all rats were sacrificed in order to analyze biomarkers of the lipid peroxidation: concentration of substances that react to thiobarbituric acids (TBARs); antioxidant status: catalase activity (CAT) and cellular activity: alkaline phosphatase activity (AP) in different organs including muscle gastrocnemius, liver, brain and blood. Results: Physical training at intensities equivalent to the metabolic transition and 25% above it improved the aerobic conditioning of the animals. Exercise-training at both intensities probably induced antioxidant compensatory responses which avoided issue lipid peroxidation. Conclusion: These results suggest that, at least in part, that the antioxidant defense mechanisms showed adaptative responses to training in the different ways, in the different organs and tissues analyzed.