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ATP浓度和缺氧暴露对大鼠脑线粒体RNA和蛋白质体外合成的影响

柳君泽, 高文祥, 蔡明春, 曹利飞, 孙秉庸

第三军医大学高原军事医学系病理生理学与高原生理学教研室,全军高原生理与高原病重点实验室.重庆 400038

摘要

大鼠急性缺氧暴露后大脑皮质线粒体RNA体外合成活性降低40%,蛋白质合成活性降低60%;慢性缺氧暴露后线粒体RNA和蛋白质合成活性分别为对照的72%和76%;ATP对正常大鼠脑线粒体RNA以及蛋白质的体外合成活性的影响均呈双相性,大于或小于1mmol/L均可产生不同程度的抑制效应。结果提示,缺氧可在转录和翻译两个水平上影响脑线粒体mtDNA的表达,而慢性缺氧暴露时,线粒体半自主性功能的改善可能是机体对缺氧适应的细胞机制之一;ATP对脑线粒体内转录和翻译活性的调节是一种经济有效的反馈调节方式。

关键词： 线粒体; 缺氧; ATP; 线粒体RNA合成; 线粒体蛋白质合成

Effects of ATP concentration and hypoxic exposure on RNA and protein synthesis activity in isolated mitochondria from rat brain

Liu Junze, Gao Wenxiang, Cai Mingchun, Cao Lifei, Sun Bingyong

Department of Pathophysiology,College of High Altitude Military Medicine,Third Military Medical University.Chongqing 400038

Abstract

The results showed that there was a 40% reduction in RNA synthesis and a 60% inhibition in protein synthesis in isolated mitochondria in vitro in acute hypoxia exposure compared to control. But in chronic hypoxic exposure, the inhibition of both RNA synthesis and protein synthesis was alleviated, being 72% and 76% of the normoxic control, respectively. Furthermore, the effect of ATP concentration in medium on mitochondrial RNA and protein synthesis in vitro showed two phases. The mitochondrial RNA and protein synthesis were inhibited when ATP concentration was either above or below 1 mmol/L in the incubation medium. These results indicate that hypoxia exposure affects the expression of mtDNA at both transcription and translation levels. It also suggests that the improvement of mitochondrial semi-automation during chronic hypoxic exposure may be at least one of the cellular mechanisms of body adaptation to hypoxia. The regulation of ATP in mitochondrial RNA and protein synthesis is therefore an economic and effective mode of regulation.

Key words: Mitochondria;Hypoxia;ATP;Mitochondrial RNA synthesis;Mitochondrial protein synthesis

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引用本文：

柳君泽, 高文祥, 蔡明春, 曹利飞, 孙秉庸. ATP浓度和缺氧暴露对大鼠脑线粒体RNA和蛋白质体外合成的影响[J]. 生理学报 2002; 54 (6): .

Liu Junze, Gao Wenxiang, Cai Mingchun, Cao Lifei, Sun Bingyong. Effects of ATP concentration and hypoxic exposure on RNA and protein synthesis activity in isolated mitochondria from rat brain. Acta Physiol Sin 2002; 54 (6): (in Chinese with English abstract).