Effects of Exercise on Oxidative Stress and its Protective Mechanism

本研究从氧应激的角度探讨有氧运动对心血管系统的影响及其保护机制。近年来的研究表明，有氧运动可增加机体氧耗，导致活性氧的产生，从而导致脂质过氧化和DNA氧化损伤。本研究探讨了有氧运动对心血管危险因素的影响，结果表明：（1）3个月的运动锻炼改善了心血管危险因素。(2)脂质过氧化反应指标TBARS（硫代巴比妥酸反应物质）在有氧运动3个月后显著降低，且TBARS水平的降低与运动次数呈正相关。(3)抗氧化酶谷胱甘肽过氧化物酶在有氧运动3个月后显著降低。(4)TBARS水平与腰臀比和Homa指数（胰岛素抵抗的指标）显著相关。(5)8-羟基鸟嘌呤（8-OHdG）含量在运动负荷后非习惯性运动组明显低于习惯性运动组，而在运动负荷后非习惯性运动组明显低于习惯性运动组。(6)而修复酶MTH-1 mRNA在习惯性运动组的表达水平高于非习惯性运动组，且非习惯性运动组的MTH-1 mRNA有运动负荷诱导表达的趋势，提示有氧运动训练对脂质和DNA的氧化损伤具有保护作用。

The aim of this study was to investigate the cardiovascular effects of the aerobic exercise from the viewpoint of oxygen stress and its protective mechanism.Recent studies reveal that exercise enhances the oxygen consumption which induces the formation of reactive oxygen species and as a result the lipid peroxidation and oxidative DNA damage can be occurred.In this study, we investigate the effects of exercise training on cardiovascular risk factors, lipid peroxidation and oxidative DNA damage.Results were as follows ;(1) Performance of 3-month exercise improved the cardiovascular risk factors.(2) TBARS(thiobarbituric acid-reactive substance), an indicator of lipid peroxidation, significantly reduced after 3-month aerobic exercise, and the reduction of TBARS level positively correlated with frequency of the exercise time.(3) Glutathione peroxidase, an antioxidant enzyme, significantly significantly reduced after 3-month aerobic exercise.(4) TBARS level significantly correlates with waist / hip ratio and Homa's Index, an indicator of insulin resistance.(5) Habitual exercise group showed higher level of 8-Hydroxy Guanine (8-OHdG) than non-habitual exercise group and the 8-OHdG level lowered after exercise load in the non-habitual exercise group but not in the habitual exercise group.(6) On the other hand, mRNA of MTH-1, a repair enzyme, was higher higher level in habitual exercise group than in the non-habitual exercise group and MTH-1 mRNA tended to be induced by exercise load in non-habitual exercise group.These results suggests that aerobic exercise training may protect against oxidative damage of lipid and DNA.