Properties of glutathione release observed during reduction of organic hydroperoxide, demethylation of aminopyrine and oxidation of some substances in perfused rat liver, and their implications for the physiological function of catalase.
Properties of glutathione release observed during reduction of organic hydroperoxide, demethylation of aminopyrine and oxidation of some substances in perfused rat liver, and their implications for the physiological function of catalase.
复制标题
灌注大鼠肝脏中有机氢过氧化物还原、氨基比林去甲基化和某些物质氧化过程中观察到的谷胱甘肽释放特性及其对过氧化氢酶生理功能的影响。
DOI：
10.1042/bj1620509
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发表时间：
1977
期刊：
影响因子：
--
通讯作者：
B. Chance
中科院分区：
文献类型：
--
作者：
N. Oshino;B. Chance
增强还原叔丁基过氧化氢谷胱甘肽过氧化物酶是伴随着减少在细胞浓度的谷胱甘肽和NADPH在离体肝细胞，导致GSSG（氧化型谷胱甘肽）从灌注大鼠肝脏的释放。这一现象由H.塞斯角格斯特内克，H.门泽尔湖02 The Dog（1972）27，171-175），可以在多种条件下观察到，不仅在有机过氧化物加速谷胱甘肽过氧化物酶反应的情况下，而且在乙醇酸盐和苄胺的氧化过程中，在苯巴比妥预处理的大鼠的肝脏中氨基比林的去甲基化过程中，以及在用3-氨基-1，2，4-三唑预处理的饥饿大鼠的肝脏中尿酸的氧化过程中。影响肝脏NADPH生成速率的代谢条件的变化会显著改变GSSG的释放速率。因此，无论是通过谷胱甘肽过氧化物酶增强谷胱甘肽氧化还是通过其他代谢途径氧化NADPH来实现，GSSG细胞浓度的增加似乎都有助于其释放。已经发现，除了己糖一磷酸分流，线粒体NADH-NADP+转氢酶反应在向谷胱甘肽过氧化物酶反应提供还原当量和维持烟酰胺核苷酸的细胞氧化还原状态中起重要作用。分光光度法分析的过氧化氢酶-H2 O2中间体的稳态浓度与同时测量的GSSG的释放速率导致的结论是，过氧化氢酶在过氧化物酶体和谷胱甘肽过氧化物酶在胞质溶胶和线粒体的细胞内区室区分这些酶的反应性从其他，并促进其在肝脏中的氢过氧化物代谢的有效合作。
The enhanced reduction of t-butyl hydroperoxide by glutathione peroxidase is accompanied by a decrease in the cellular concentration of both glutathione and NADPH in isolated liver cells, resulting in the release of GSSG (oxidized glutathione) from the perfused rat liver. This phenomenon, first reported by H. Sies, C. Gerstenecker, H. Menzel & L. Flohé (1972) (FEBS Lett. 27, 171-175), can be observed under a variety of conditions, not only with the acceleration of the glutathione peroxidase reaction by organic peroxides, but also during the oxidation of glycollate and benzylamine, during demethylation of aminopyrine in the liver of the phenobarbital-pretreated rat and during oxidation of uric acid in the liver of the starved rat pretreated with 3-amino-1,2,4-triazole. The rate of release of GSSG is altered markedly by changes in the metabolic conditions which affect the rate of hepatic NADPH generation. Thus, regardless of whether achieved by enhanced oxidation of glutathione by glutathione peroxidase or by oxidation of NADPH through other metabolic pathways, an increase in the cellular concentration of GSSG appears to facilitate its release. It has been found that, in addition to the hexose monophosphate shunt, the mitochondrial NADH-NADP+ transhydrogenase reaction plays an important role in supplying reducing equivalents to the glutathione peroxidase reaction and in maintaining the cellular oxidation-reduction state of the nicotinamide nucleotides. Spectrophotometric analysis of the steady-state concentration of the catalase-H2O2 intermediate with simultaneous measurement of the rate of release of GSSG leads to the conclusion that intracellular compartmentation of catalase in the peroxisomes and glutathione peroxidase in the cytosol and mitochondria distinguishes the reactivities of these enzymes one from the other, and facilitates their effective cooperation in hydroperoxide metabolism in the liver.