NADH-dependent microsomal interaction with ferric complexes and production of reactive oxygen intermediates.
NADH-dependent microsomal interaction with ferric complexes and production of reactive oxygen intermediates.
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DOI：
10.1016/0003-9861(89)90400-1
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发表时间：
1989-12
影响因子：
3.9
通讯作者：
E. Kukiełka;A. Cederbaum
中科院分区：
文献类型：
--
作者：
E. Kukiełka;A. Cederbaum
NADPH 与铁络合物催化微粒体生成活性氧中间体的相互作用已得到充分研究。进行实验来表征 NADH 与各种铁螯合物相互作用以促进微粒体脂质过氧化和 .OH 样物质生成的能力。在 NADH 和铁存在的情况下，微粒体产生 .OH，通过多种 .OH 清除剂的氧化来评估。 NADH 依赖性 .OH 的生成率为 NADPH 催化反应的 50% 至 80%。二甲亚砜叔丁醇的氧化受到过氧化氢酶和竞争性·OH清除剂的抑制，但不受超氧化物歧化酶或一氧化碳的抑制。 EDTA 铁和二亚乙基三胺五乙酸铁 (DTPA) 可有效催化 NADH 依赖性 .OH 的产生，而 ATP 铁和柠檬酸铁的催化剂效果较差。所有这些铁螯合物在 NADH（和 NADPH）存在下都被微粒体还原。在 NADH 存在下，通过添加 EDTA 铁刺激反应产生 H2O2，这与 .OH 产量的增加一致。后者似乎受到 H2O2 生成速率的限制，而不是铁螯合物还原速率的限制。 NADH 依赖性脂质过氧化反应远低于 NADPH 催化的反应，并且与 .OH 的生成相比，对三价铁复合物的催化反应表现出相反的反应，因为硫代巴比妥酸反应物质的产量随着铁-ATP 和 柠檬酸盐的增加而增加，但铁-EDTA 或 -DTPA 则不增加，并且不受过氧化氢酶、SOD 或 .OH 清除剂的影响。这些结果表明，NADH 可以支持铁螯合物的微粒体还原，随后产生 .OH 样物质和脂质过氧化。 NADH 依赖性反应在铁螯合物的催化效果和对自由基清除剂的敏感性方面的响应模式与 NADPH 的反应模式相似。乙醇的许多代谢作用归因于乙醇脱氢酶氧化产生 NADH。由于细胞质通常保持高度氧化的 NAD+/NADH 氧化还原比，因此有趣的是推测乙醇氧化导致的 NADH 可用性增加可能支持铁复合物的微粒体还原，并随后产生活性氧中间体。
The interaction of NADPH with ferric complexes to catalyze microsomal generation of reactive oxygen intermediates has been well studied. Experiments were carried out to characterize the ability of NADH to interact with various ferric chelates to promote microsomal lipid peroxidation and generation of .OH-like species. In the presence of NADH and iron, microsomes produced .OH as assessed by the oxidation of a variety of .OH scavenging agents. Rates of NADH-dependent .OH production were 50 to 80% those of the NADPH-catalyzed reaction. The oxidation of dimethyl sulfoxide ort-butyl alcohol was inhibited by catalase and competitive .OH scavengers but not by superoxide dismutase or carbon monoxide. NADH-dependent .OH production was effectively catalyzed by ferric-EDTA and ferric-diethylenetriaminepentaacetic acid (DTPA), whereas ferric-ATP and ferric-citrate were poor catalysts. All these ferric chelates were reduced by microsomes in the presence of NADH (and NADPH). H2O2was produced in the presence of NADH in a reaction stimulated by the addition of ferric-EDTA, consistent with the increase in .OH production. The latter appeared to be limited by the rate of H2O2generation rather than the rate of reduction of the ferric chelate. NADH-dependent lipid peroxidation was much lower than the NADPH-catalyzed reaction and showed an opposite response to catalysis by ferric complexes compared to .OH generation as production of thiobarbituric acid-reactive material was increased with ferric-ATP and -citrate, but not with ferric-EDTA or -DTPA, and was not affected by catalase, SOD, or .OH scavengers. These results indicate that NADH can support microsomal reduction of ferric chelates, with the subsequent production of .OH-like species and peroxidation of lipids. The pattern of response of the NADH-dependent reactions with respect to catalytic effectiveness of ferric chelates and sensitivity to radical scavengers is similar to that found with NADPH. Many of the metabolic actions of ethanol have been ascribed to production of NADH as a consequence of oxidation by alcohol dehydrogenase. Since the cytosol normally maintains a highly oxidized NAD+/NADH redox ratio, it is interesting to speculate that increased availability of NADH from the oxidation of ethanol may support microsomal reduction of iron complexes, with the subsequent generation of reactive oxygen intermediates.