ACTION OF PARAQUAT AND DIQUAT ON RESPIRATION OF LIVER CELL FRACTIONS
ACTION OF PARAQUAT AND DIQUAT ON RESPIRATION OF LIVER CELL FRACTIONS
复制标题
DOI：
10.1042/bj1090757
复制
发表时间：
1968-01-01
影响因子：
4.1
通讯作者：
GAGE, JC
中科院分区：
文献类型：
--
作者：
GAGE, JC
1.百草枯和敌草快只会略微增加大鼠肝脏线粒体的摄氧量，而且很可能不会穿透线粒体膜。2.在抗霉素A或Amytal抑制的线粒体片段中，这两种物质都以NADH或β-羟基丁酸酯为底物刺激氧摄取，但以琥珀酸酯为底物则不刺激。呼吸链的NADH脱氢酶似乎参与其中，在一个位点上仅被Amytal部分抑制。3.敌草快在大鼠肝微粒体中刺激NADPH氧化酶活性，百草枯在较小程度上刺激NADPH氧化酶活性;敌草快还引起NADH氧化酶活性的发展。这种作用不受一氧化碳或对氯汞苯甲酸盐的抑制，并且可能是黄素蛋白参与了一种不需要巯基的机制。4.一个氧分子可以在受刺激的微粒体系统中氧化两个NADPH分子，所产生的过氧化氢被微粒体中的过氧化氢酶活性分解。5.敌草快可刺激微粒体后可溶性组分中的NADH氧化酶和NADPH氧化酶的活性;所涉及的酶可能是DT-心肌黄酶。6.这些反应的机制和它们的意义有关的双嘧磺隆化合物的毒性进行了讨论。
1. Paraquat and diquat produce only a slight increase in the oxygen uptake of rat liver mitochondria, and it is likely that they do not penetrate the mitochondrial membrane. 2. In mitochondrial fragments inhibited by antimycin A or by Amytal, both substances stimulate oxygen uptake with NADH or β-hydroxybutyrate as substrate but not with succinate. The NADH dehydrogenase of the respiratory chain appears to be involved, at a site only partially inhibited by Amytal. 3. An NADPH oxidase activity is stimulated in rat liver microsomes by diquat, and to a smaller extent by paraquat; diquat also causes an NADH oxidase activity to develop. The effect is not inhibited by carbon monoxide orp-chloromercuribenzoate, and it is probable that a flavoprotein is involved by a mechanism not requiring thiol groups. 4. One molecule of oxygen can oxidize two molecules of NADPH in the stimulated microsomal system, the hydrogen peroxide produced being broken down by a catalase activity in the microsomes. 5. Diquat can stimulate NADH oxidase and NADPH oxidase activity in the postmicrosomal soluble fraction; the enzyme involved may be DT-diaphorase. 6. The mechanism of these reactions and their significance in relation to the toxicity of the dipyridilium compounds are discussed.