Production of reactive oxygen species by mitochondria - Central role of complex III
Production of reactive oxygen species by mitochondria - Central role of complex III
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DOI：
10.1074/jbc.m304854200
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发表时间：
2003-09-19
影响因子：
4.8
通讯作者：
Lesnefsky, EJ
中科院分区：
文献类型：
--
作者：
Chen, Q;Vazquez, EJ;Lesnefsky, EJ
在包括心肌缺血和再灌注的病理条件下，线粒体呼吸链是活性氧（ROS）的主要来源。在缺血前即刻通过抑制剂鱼藤酮限制电子传递减少心肌细胞中ROS的产生并减少对线粒体的损伤。我们问，如果活性氧生成的完整的线粒体在氧化过程中的复合物I底物（谷氨酸，丙酮酸/苹果酸）发生从复合物I或III。研究了Sprague-Dawley大鼠心脏线粒体和相应的亚线粒体颗粒的ROS产生。使用amplex red测定法测量ROS作为H2 O2。在线粒体氧化复合物I底物，鱼藤酮抑制没有增加过氧化氢。抗霉素A的存在下，复合物I或II底物的氧化显着增加H2 O2。鱼藤酮可以阻止抗霉素A诱导的线粒体中复合物I底物产生H2 O2，但不能阻止复合物II底物产生H2 O2。过氧化氢酶清除过氧化氢。与完整的线粒体相反，阻断复合物I与鱼藤酮显着增加H2 O2生产从亚线粒体颗粒氧化复合物I底物NADH。ROS由复合物I通过位于内膜基质侧的NADH脱氢酶产生，并通过基质抗氧化防御在线粒体中消散。然而，在亚线粒体颗粒缺乏抗氧化防御活性氧从复杂的I可用于检测。在线粒体中，复合物III是复合物I底物氧化过程中ROS产生的主要位点，鱼藤酮通过限制电子流进入复合物III来保护。
The mitochondrial respiratory chain is a major source of reactive oxygen species (ROS) under pathological conditions including myocardial ischemia and reperfusion. Limitation of electron transport by the inhibitor rotenone immediately before ischemia decreases the production of ROS in cardiac myocytes and reduces damage to mitochondria. We asked if ROS generation by intact mitochondria during the oxidation of complex I substrates ( glutamate, pyruvate/malate) occurred from complex I or III. ROS production by mitochondria of Sprague-Dawley rat hearts and corresponding submitochondrial particles was studied. ROS were measured as H2O2 using the amplex red assay. In mitochondria oxidizing complex I substrates, rotenone inhibition did not increase H2O2. Oxidation of complex I or II substrates in the presence of antimycin A markedly increased H2O2. Rotenone prevented antimycin A-induced H2O2 production in mitochondria with complex I substrates but not with complex II substrates. Catalase scavenged H2O2. In contrast to intact mitochondria, blockade of complex I with rotenone markedly increased H2O2 production from submitochondrial particles oxidizing the complex I substrate NADH. ROS are produced from complex I by the NADH dehydrogenase located in the matrix side of the inner membrane and are dissipated in mitochondria by matrix antioxidant defense. However, in submitochondrial particles devoid of antioxidant defense ROS from complex I are available for detection. In mitochondria, complex III is the principal site for ROS generation during the oxidation of complex I substrates, and rotenone protects by limiting electron flow into complex III.