Oxidant/antioxidant response during fasting and exhaustive swimming in the kidney of trained mice

There are no reports on the oxidant/antioxidant response in the kidney of trained mice, during the process of short-term fast or exhaustive exercise. Trained mice (TR) and untrained (NO) but only adapted to swimming were submitted to fasting or exhaustive swimming for 2, 4 and 6 h, and observed at 4 and 24 h of recovery. Measurements were made of the concentration of Thiobarbituric acid reactive substance (TBARS), total antioxidant capacity (TAC) and enzyme activity (glutathione peroxidase (GPx), superoxide dismutase (SOD) and catalase (CAT)), and were compared between the two groups. During fasting there was a sharp increase in all enzymes in the NO group and stability of all parameters in the TR group. Contrarily, during recovery from the fast, an increase was found in all parameters only in the TR group, and this was at the fourth hour. During exhaustive swimming (subtracting the effect of fasting), there was stability in TBARS and enzymes in the TR group, and a sharp decrease in SOD and CAT in the NO group. In both groups, a similar increase in the TAC was observed, reaching its maximum level at 2 h of swimming, followed by a return to basal levels. There are indices of non-enzymatic antioxidant components mobilization during exercise in both groups. The significant change in the antioxidant state during fasting as well as exhaustive exercise in the NO group probably represents a response to greater ROS production.   Key words: Training, oxidative stress, antioxidant enzymes, exhaustive exercise.