Involvement of Oxygen Radicals in Aging

由于氧自由基的代谢率与物种的寿命呈负相关关系，因此认为氧自由基参与了物种的衰老过程。组织氧化损伤的直接证据之一是在正常人血浆中存在过氧化胆固醇酯。这种过氧化氢在大鼠血浆中的含量高于人类。结果表明氧化应激与衰老呈正相关。同样有趣的是，无抗体血症的大鼠，很容易被某些胺诱导癌症，有更高的过氧化氢水平。接下来，我可以开发磷脂的氢过氧化物的检测方法，如磷脂酰乙醇胺、磷脂酰丝氨酸、磷脂酰肌醇和心磷脂。大鼠肝脏和心脏未检测到磷脂氢过氧化物。这可能是由于谷胱甘肽过氧化物酶对氢过氧化物的还原作用。因此，有必要对游离脂肪酸的氧化产物进行检测。结果表明，氧化应激大鼠的氧化产物中有一种氧化产物增加，单丹嘧啶的衍生化对皮摩尔水平的检测非常有用。

It is considered that oxygen radicals should be involved in the aging process since the life time of species inversely correlates with metabolic rates of them. One of the direct evidence for the oxidative damage of the tissue is the presence of cholesteryl ester hydroperoxide in normal human plasma. This hydroperoxide levels in rat plasmas are higher than those in humans. This results indicate the positive correlation between the oxidative stress and aging. It is also interesting that analbuminemic rats, which is very susceptible to the induction of cancers by certain amines, have higher hydroperoxide levels.Next I could develop the method for the detection of hydroperoxides of phospholipids such as phosphatidylethanolamine, phosphatidylserine, phosphatidylinositol, and cardiolipin. However, no phospholipid hydroperoxides were detected in rat liver and heart. This is likely due to the reduction of the hydroperoxides by glutathione peroxidase.Therefore, it is necessary to detect the oxidation products of free fatty acids. It is found that the derivatization of them by monodansylcadaverine is very useful for the picomole level detection and one of the oxidation products increased in the rats under oxidative stress.