In vivo labeling of mitochondrial complex I (NADH:ubiquinone oxidoreductase) in rat brain using [3H]dihydrorotenone
In vivo labeling of mitochondrial complex I (NADH:ubiquinone oxidoreductase) in rat brain using [3H]dihydrorotenone
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DOI：
10.1046/j.1471-4159.2000.0752611.x
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发表时间：
2000-12-01
影响因子：
4.7
通讯作者：
Greenamyre, JT
中科院分区：
文献类型：
--
作者：
Talpade, DJ;Greene, JG;Greenamyre, JT
线粒体能量代谢缺陷与多种神经退行性疾病有关。复合物 I（NADH：泛醌氧化还原酶）活性缺陷在莱伯遗传性视神经病以及可能的帕金森病中发挥着关键作用，但无法评估活体大脑中的这种酶。我们之前描述了使用[H-3]二氢鱼藤酮（[H-3]DHR）与复合物I结合的体外定量放射自显影测定。我们现在开发了一种在静脉内给药后使用[H-3]DHR结合的体内放射自显影测定复合物I。体内 [H-3]DHR 结合具有区域异质性，并且大脑摄取迅速。与神经胶质细胞相比，神经元中的结合更加丰富，而白质的结合水平最低。体内[H-3]DHR结合通过局部和全身输注鱼藤酮而显着减少，并通过局部NADH施用而增强。体内[H-3]DHR结合的区域水平与复合物II（琥珀酸脱氢酶）和复合物IV（细胞色素氧化酶）的体外活性之间存在极好的相关性，这表明电子传递链的这些成分的化学计量在整个大脑区域中相对恒定。体内检测复合物 I 的能力应该为研究这种线粒体酶在活体大脑中的状态提供一个有价值的工具，并为人类复合物 I 的潜在成像技术提供建议。
Defects in mitochondrial energy metabolism have been implicated in several neurodegenerative disorders. Defective complex I (NADH:ubiquinone oxidoreductase) activity plays a key role in Leber's hereditary optic neuropathy and, possibly, Parkinson's disease, but there is no way to assess this enzyme in the living brain. We previously described an in vitro quantitative autoradiographic assay using [H-3]dihydrorotenone ([H-3]DHR) binding to complex I. We have now developed an in vivo autoradiographic assay for complex I using [H-3]DHR binding after intravenous administration. In vivo [H-3]DHR binding was regionally heterogeneous, and brain uptake was rapid. Binding was enriched in neurons compared with glia, and white matter had the lowest levels of binding. In vivo [H-3]DHR binding was markedly reduced by local and systemic infusion of rotenone and was enhanced by local NADH administration. There was an excellent correlation between regional levels of in vivo [H-3]DHR binding and the in vitro activities of complex II (succinate dehydrogenase) and complex IV (cytochrome oxidase), suggesting that the stoichiometry of these components of the electron transport chain is relatively constant across brain regions. The ability to assay complex I in vivo should provide a valuable tool to investigate the status of this mitochondrial enzyme in the living brain and suggests potential imaging techniques for complex I in humans.