Lee D W, Yu B P
Department of Physiology, University of Texas Health Science Center, San Antonio 78284-7756.
Aging (Milano). 1990 Dec;2(4):357-62. doi: 10.1007/BF03323951.
Reducing dietary intake has been shown to be the most effective means for modulating aging processes in laboratory rodents. Dietary restriction has also been shown to be a modulator of membrane lipid peroxidation and cytosolic antioxidant status. In the present study, anti-radical action of dietary restriction was investigated further by quantitating the formation of the superoxide radical, hydroxyl radical and hydrogen peroxide by liver microsomes from rats of various ages. The results show that the ad libitum fed group maintained a higher production of superoxide and hydroxyl radicals when compared to the food restricted group of the same age. Hydrogen peroxide formation followed the same trend but was statistically greater only at 3 and 6 months of age. The food restricted group tended to show a higher superoxide dismutase (SOD) activity in both cytosolic and mitochondrial fractions than ad libitum fed controls. These data indicate that the free radical activity observed in the liver microsomes of ad libitum fed rats can be attenuated by dietary restriction, thereby providing a possible biochemical mechanism for its anti-lipoxidative action on membrane lipid peroxidation as reported in an earlier study. This action may in part underlie the life span-prolonging action of food restriction.
减少饮食摄入量已被证明是调节实验啮齿动物衰老过程的最有效手段。饮食限制也已被证明是膜脂质过氧化和胞质抗氧化状态的调节剂。在本研究中，通过定量不同年龄大鼠肝脏微粒体中超氧自由基、羟自由基和过氧化氢的形成，进一步研究了饮食限制的抗自由基作用。结果表明，与相同年龄的食物限制组相比，自由采食组超氧自由基和羟自由基的产生量更高。过氧化氢的形成也呈现相同趋势，但仅在3个月和6个月时在统计学上更高。食物限制组在胞质和线粒体部分的超氧化物歧化酶（SOD）活性往往比自由采食对照组更高。这些数据表明，自由采食大鼠肝脏微粒体中观察到的自由基活性可通过饮食限制减弱，从而为其如早期研究所报道的对膜脂质过氧化的抗脂质氧化作用提供了一种可能的生化机制。这一作用可能部分是食物限制延长寿命作用的基础。
