Effect of aging and physical training on hydroxyl radical generation and scavenging capacity.

本文研究了运动对运动和久坐不动的幼年和老年大鼠体内活性氧产生和清除自由基能力的影响。运动增加了运动后幼鼠所有组织中的羟基自由基含量，但血浆中的羟基自由基含量除外。在老年大鼠中，血浆、心脏和骨骼肌中自由基的基础水平显著升高，而肝脏中的自由基基础水平显著下降；在大多数情况下，体力活动使其降低到年轻大鼠的水平。随着运动的进行，幼鼠血浆、心脏和骨骼肌中还原型谷胱甘肽含量显著增加，肝脏中氧化还原型谷胱甘肽含量显著降低，脑和白色腓肠肌中含量显著增加。这些组织中的总谷胱甘肽水平也以类似的方式变化，表明谷胱甘肽是从肝脏的池中释放出来的。在允许自愿跑步5周的大鼠中，这种影响比久坐不动的大鼠更明显。久坐不动的幼鼠血浆、心脏和比目鱼肌中还原型谷胱甘肽与总还原型谷胱甘肽的比值在运动后有所增加，而在有体力活动的幼鼠中进一步增加。在老年大鼠中，血浆、心脏、肝脏和大脑中还原的谷胱甘肽水平增加，即使总量减少。这些结果表明，体力活动增强了机体抵御氧化应激的内源性能力。在老年大鼠中，即使谷胱甘肽合成减少，再生能力似乎也会增加，以补偿增加的氧化应激。

The effects of exercise on the generation of active oxygen species and radicalscavenging capacity were studied in physically active and sedentary young and old rats. Exercise increased the hydroxyl radical content in all tissues of physically active young rats, except in the plasma. In old rats, the basal level of the radical increased significantly in plasma, heart, and skeletal muscles, but decreased in liver ; and physical activity decreased it to that of young ones in most cases. With exercise, the content of reduced glutathione increased in plasma, heart, and skeletal muscles of young rats, whereas that of oxidized glutathione markedly decreased in liver and increased in brain and white gastrocnemius muscle. The total glutathione levels in these tissues changed in a similar way, indicating that glutathione was released from the pool in the liver. In rats allowed to run voluntarily for 5 weeks, the effects were more pronounced than in the sedentary ones. The ratio of reduced to total glutathione, which indicates the capacity to reduce glutathione, increased in plasma, heart, and soleus muscle of sedentary young rats after exercise, and increased further in those with the physical activity. In old rats, the reduced glutathione level increased in plasma, heart, liver, and brain, even though the total decreased. These results suggest that physical activity enhances the endogenous ability to defend against oxidative stress. In old rats, even though glutathione synthesis is decreased, the regenerating capacity seems to be increased in order to compensate for the increased oxidative stress.