Sohal R S, Brunk U T
Department of Biological Sciences, Southern Methodist University, Dallas, TX 75275.
Mutat Res. 1992 Sep;275(3-6):295-304. doi: 10.1016/0921-8734(92)90033-l.
Mitochondria are the major intracellular producers of O2- and H2O2. The level of oxidative stress in cells, as indicated by the in vivo exhalation of alkanes and the concentration of molecular products of oxy-radical reactions, increases during aging in mammals as well as insects. In this paper, we discuss the relationship between mitochondrial generation of O2- and H2O2, and the aging process. The rate of mitochondrial O2- and H2O2 generation increases with age in houseflies and the brain, heart and liver of rat. This rate has been found to correspond to the life expectancy of flies and to the maximum life span potential (MLSP) of six different mammalian species, namely, mouse, rat, guinea pig, rabbit, pig and cow. In contrast, the level of antioxidant defenses provided by activities of superoxide dismutase, catalase, glutathione peroxidase and glutathione concentration neither uniformly declines with age nor corresponds to variations in MLSP of different mammalian species. It is argued that the rate of mitochondrial O2- and H2O2 generation rather than the antioxidant level may act as a longevity determinant.
线粒体是细胞内产生超氧阴离子（O2-）和过氧化氢（H2O2）的主要场所。正如体内烷烃呼出量和氧自由基反应分子产物浓度所表明的那样，细胞内的氧化应激水平在哺乳动物和昆虫衰老过程中都会升高。在本文中，我们讨论了线粒体产生O2-和H2O2与衰老过程之间的关系。家蝇以及大鼠的脑、心脏和肝脏中线粒体产生O2-和H2O2的速率会随着年龄的增长而增加。已发现该速率与家蝇的预期寿命以及六种不同哺乳动物物种（即小鼠、大鼠、豚鼠、兔子、猪和牛）的最大寿命潜力（MLSP）相对应。相比之下，由超氧化物歧化酶、过氧化氢酶、谷胱甘肽过氧化物酶活性和谷胱甘肽浓度所提供的抗氧化防御水平既不会随着年龄的增长而均匀下降，也与不同哺乳动物物种的MLSP变化不对应。有人认为，线粒体产生O2-和H2O2的速率而非抗氧化水平可能是寿命的决定因素。
