Evaluation of the effects of different intensities of forced running wheel exercise on oxidative stress biomarkers in muscle, liver and serum of untrained rats

Exercise induces different effects on antioxidant status depending on its intensity. The forced running wheel (FRW) model maintains a constant intensity and volume during exercise. The aim of the present study was to investigate the effects of FRW exercise at different running speeds on several serum biochemical parameters of liver and muscle functions and on oxidative stress biomarkers in skeletal muscle, liver and serum in the rat. Thirty-six male Wistar rats were randomly divided into six groups. Five groups participated in constant power tests at intensities of 10, 13, 14.5, 16, and 17.5 m/min, and a non-exercise group was chosen as the control. Serum, muscle and liver tissues were collected after the tests and analyzed. At speeds >16 m/min, exercise on an FRW significantly increased several serum biochemical parameters, malondialdehyde level and superoxide dismutase activity in all tissues of exercise rats compared with control rats; FRW exercise also increased catalase activity in the liver and glutathione S-transferase activity in muscle, whereas it decreased glutathione level in all tissues and catalase activity in muscle and serum. These data suggest that FRW exercise in rats activates an adaptation of the antioxidant system response in skeletal muscle at speeds <16 m/min, whereas it induces oxidative stress at higher speeds in muscle, liver and serum. In addition, we observed a correlation between the systematic and local oxidative stress status in rats after exercise on FRW.