呼吸链温和解偶联:运动中骨骼肌线粒体抗氧化分子调控的早期事件  

The Mild Uncoupling of Respiratory Chain: An Early Event of Anti-oxidative Molecular Regulation in Muscle Mitochondria during Prolonged Exercise

作　　者：姜宁[1] 张桂忠[1] 马国栋[1] 曹东宁[1] 薄海[1] 文立[1] 张勇[1] 刘树森[2] 

机构地区：[1]天津体育学院运动医学研究所,运动人体科学系天津300381 [2]中国科学院动物研究所生物膜与膜生物工程国家重点实验室

出　　处：《中国运动医学杂志》2005年第5期535-540,共6页Chinese Journal of Sports Medicine

基　　金：国家自然科学基金No.30270638和No.30470837共同资助

摘　　要：目的:研究急性运动诱导线粒体活性氧(ROS)生成的过程中,线粒体内解偶联蛋白(UCPs)介导的温和解偶联(milduncoupling)和抗氧化酶这两种抗氧化体系可能的分工与协同关系及其生物学意义。方法:以SD大鼠3级递增负荷跑台运动为实验模型,分别选取安静态、运动45min、90min、120min和150min为实验观察点(timecourse),测定骨骼肌线粒体ROS生成和脂质过氧化水平(MDA)、线粒体Mn-SOD酶活性、Mn-SOD和解偶联蛋白3(UCP-3)mRNA及蛋白表达。结果:运动过程中ROS生成呈先上升后下降的变化趋势,在运动120min达到峰值,其中运动45min、90min、120min和150min时均较安静时呈显著性升高(分别为P<0.05、P<0.001、P<0.001和P<0.01),150min时下降并具有显著性(P<0.001)。线粒体MDA含量总体呈上升趋势,但变化无显著性。运动过程中Mn-SOD酶活性及其mRNA和蛋白表达水平均无显著性变化,而UCP-3mRNA和蛋白表达水平总体呈上升趋势。其中UCP-3mRNA在运动至90min、120min、150min时较安静时均呈显著性升高(分别为P<0.001、P<0.01和P<0.01),其蛋白表达水平相对滞后一个时间段,运动120min、150min时较安静时显著升高(均为P<0.001)。结论:长时间运动过程中,以UCP-3的先行诱导表达对骨骼肌线粒体氧化还原状态进行调节,相对于Mn-SOD的抗氧化作用,UCP-3的诱导表达是运动中抗氧化的“早期事件”。Objective The present research was to explore a possible coordination between the mitochondrial UCPs - mediated uncoupling and the antioxidant enzymes during the exercise - induced ROS generation. Methods SD rats were divided into 5 groups to stay at rest or run for 45, 90, 120 or 150min, respectively, on the treadmill with incremental protocol and sacrificed at rest or immediately after the exercise time courses. The following parameters of skeletal muscle tissue or its mitochondria were determined： （ 1 ） Mitochondrial ROS generation rate; （2） Malondialdehyde （MDA） in skeletal muscular mitochondria; （3） Mitochondrial Mn - SOD enzyme activity; （4） Mn - SOD and UCP- 3 mRNA expression in skeletal muscle tissue using RT - PCR; （5） Mn - SOD and UCP - 3 protein by Western - Blotting. Results Mitochondrial ROS generation climbed to the peak at the point of 120min and subsequently declined, with significantly higher levels at 45, 90, 120 and 150min in comparison with that at rest （ P 〈 0.05, P 〈 0.001, P 〈 0.001 and P 〈 0.01 respectively）, and with obviously lower level at 150min in comparison with that at 120min （ P 〈 0.001） ; Mitochondrial MDA content slowly increased during exercise without significance. No significant changes in Mn - SOD activity, the level of Mn - SOD mRNA or protein expression were found in the course of exercise. There were remarkably higher levels of UCP - 3 mRNA at the point of 90, 120 and 150min （ P 〈 0.001, P 〈 0.01 and P 〈 0.01, respectively）, and protein content at the point of 120 and 150min （ P 〈 0.001 for both） in comparison with that at rest. Conclusions It could be speculated that the mitochondrial redox status was regulated by increased expression of UCP - 3 at the beginning of the acute exercise. The induced - expression of UCP - 3 was an earlier event relative to Mn - SOD in the anti - oxidation defense.

关 键 词：骨骼肌线粒体 ROS 急性运动 UCP-3 解偶联 MN-SOD 抗氧化 骨骼肌线粒体 解偶联蛋白 抗氧化体系 运动诱导 分子调控 早期 蛋白表达水平 脂质过氧化水平 呼吸链 

分 类 号：G804.7[文化科学—运动人体科学]