运动、锌铜营养与自由基代谢—Ⅴ.锌缺乏对运动小鼠体内自由基生成与清除的影响

EFFECT OF ZINC DEFICIENCY ON THE FREE RADICAL GENERATION AND THE FREE RADICAL ELIMINATION IN EXERCISED MICE

离乳Balb/c小鼠48只,按性别体重随机分成缺锌、对饲对照及自由进食对照三大组,每大组又分成运动和不运动两组。6周后进行锌、铜、丙二醛(MDA)、超氧化物歧化酶(SOD)、谷光甘肽过氧化物酶(GSH-Px)及过氧化氢酶(CAT) 的测定,并对肝组织直接进行低温ESR(电子自旋共振)波谱分析。实验结果提示:锌缺乏将导致运动及不运动小鼠体内的自由基生成增加和清除减少;运动训练虽可使正常小鼠体内的自由基防御能力加强,但却对锌缺乏小鼠体内的SOD、GSH-Px和CAT均无显著作用,相反,运动训练还可以使缺锌小鼠肝线粒体内的脂质过氧化产物进一步显著增加。

The purpose of this study was to investigate the effect of zinc deficiency on the free radical generationand the free radical elimination in exercised mice. 16 weanling mice were fed a zinc-deficient diet containing1.6 ppm zinc, and the other 32 in two control groups were pair-fed or fed ad libitum a zinc-adequate dietcontaining 51.6 ppm zinc. Half of each group received an exercise training programme consisting of swim-ming for 60 min per day in deionized water. The diets and the exercise programme persisted for 6 wks. Freeradicals in liver were directly detected by electron spin resonance (ESR) techniques and the zinc, copper,malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT)were also determined. The results showed that (1) exercise training increased the requirement of zinc; (2)zinc deficiency would lead to an increased free radical generation, lipid peroxidation and a decreased hepaticCuZn-SOD activity in both sedentary and exercised mice; (3) exercise training had no effects on the MDAproduction in mice fed ad libitum the zinc-adequate diet, but further increased the hepatic mitochondrialMDA formation in zinc-deficient animals; (4) exercise training did strengthen the free radical eliminationbut zinc deficiency would abolish the exercise-induced adaptation; (5) additionally, it could also be conclu-ded from this study that food restriction should not be encouraged in exercised subjects.