EFFECTS OF ENDURANCE PHYSICAL-TRAINING ON HYDROXYL RADICAL GENERATIONIN RAT-TISSUES

physical exercise is known to increase oxygen consumption to compensat e for enhanced ATP consumption and thus to induce oxidative stress in tissues. Our previous data indicate that training significantly increa sed the hydroxyl radical level in rat tissues after physical exercise, but reduced the basal level in aged rats. This result suggests the pa radoxical effect of physical training, which may be to increase or sca venge reactive oxygen species (ROS) generated by physical exercise. In this paper, the effects of training on the levels of hydroxyl radical s and the anti-oxidative glutathione system, were examined in rats. Af ter 3 weeks' training, rats were sacrificed at rest or after treadmill running, and the levels of hydroxyl radicals trapped with salicylic a cid, reduced (GSH); and oxidized glutathione (GSSG) in tissues were qu antified by high-performance liquid chromatography-electrochemical det ection (HPLC-ECD). Endurance training reduced the basal level of hydro xyl radicals significantly in plasma and soleus muscle. In liver and b rain a similar tendency was observed, but the difference was not stati stically significant. In liver the basal level of GSH increased signif icantly after training. Slower training with longer duration reduced t he basal levels of hydroxyl radical in plasma more markedly than more intense training. These results suggest that endurance exercise can in crease the anti-oxidative capacity in rats.