It is thought that chronic exercise increases the antioxidative capacity in body, and raises oxidative stress tolerance. The purpose of this study was to investigate the effect of exercise training on the oxidative stress tolerance in liver using ischemia-reperfusion (I/R) model. Sprague Dawley rats of 10 wk old were divided into groups: rested-sham, exercised-sham rested-I/R, and exercised-I/R. Running exercise was carried out 5 day/wk in the exercise groups. After 4 wk, I/R consisting from 30 min of ischemia and 3 hr of reperfusion was performed by regulated blood flow in hepatic artery and portal vein in the I/R groups. Glutamic-oxaloacetic transaminase, glutamic-pyruvic transaminase and lipid peroxide concentration in serum increased by ischemia-reperfusion while the significant change by exercise training was not seen. Although 4-hydroxy-2-nonenal modified protein in liver was increased by I/R, it was blunted by training. In the exercise group, the level of glutathion peroxidase in liver was significantly increased after ischemia-reperfusion. These results show that the oxidative injury in liver induced by I/R is attenuated by training, resulting from exercise training increases the induction of antioxidant enzymes on oxidative stress. The present study suggests that chronic exercise has beneficial effect as preconditioning against oxidative stress.

DESCENTE SPORTS SCIENCE Vol.24/THE DESCENTE AND ISHIMOTO MEMORIAL FOUNDATION FOR THE PROMOTION SPORTS SCIENCE