Relative contributions of heart mitochondria glutathione peroxidase and catalase to H2O2 detoxification in in vivo conditions
Relative contributions of heart mitochondria glutathione peroxidase and catalase to H2O2 detoxification in in vivo conditions
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DOI：
10.1016/s0891-5849(02)01016-x
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发表时间：
2002-11-01
影响因子：
7.4
通讯作者：
Cadenas, E
中科院分区：
文献类型：
--
作者：
Antunes, F;Han, D;Cadenas, E
本研究旨在评估谷胱甘肽过氧化物酶和过氧化氢酶对心脏线粒体基质中过氧化氢解毒的相对贡献。为此，使用大鼠心脏的线粒体膜泡以尽量减少微过氧化物酶体的污染，并测定了两种酶活性的动力学速率常数以及模拟曲线。结果表明，即使在强氧化条件下，如在缺血 - 再灌注过程中出现的、涉及谷胱甘肽大量耗竭和高过氧化氢浓度的情况，过氧化氢酶对心脏线粒体中过氧化氢去除的贡献也不显著。相反，维持心脏线粒体基质中过氧化氢的稳态水平似乎是谷胱甘肽过氧化物酶的作用范围。有人提出，在心脏线粒体中发现的少量过氧化氢酶的生理作用与其过氧化物酶活性而非过氧化氢酶活性有关。（C）2002爱思唯尔科学公司
This study was aimed at assessing the relative contributions to H2O2 detoxification by glutathione peroxidase and catalase in the mitochondrial matrix of heart. For this purpose, mitoplasts from rat heart were used in order to minimize contamination with microperoxisomes, and the kinetic rate constants of both enzymatic activities were determined along with a simulation profile. Results show that the contribution of catalase to H2O2 removal in heart mitochondria is not significant, even under strong oxidative conditions, such as those achieved in ischemia-reperfusion and involving extensive glutathione depletion and high H2O2 concentrations. Conversely, maintenance of the steady state levels of H2O2 in the heart mitochondrial matrix seems to be the domain of glutathione peroxidase. It is suggested that the physiological role of the low amounts of catalase found in heart mitochondria is related to its peroxidatic rather than catalatic activity. (C) 2002 Elsevier Science Inc.