Mitochondria and microsomal membranes have a free radical reductase activity that prevents chromanoxyl radical accumulation.
Mitochondria and microsomal membranes have a free radical reductase activity that prevents chromanoxyl radical accumulation.
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DOI：
10.1016/0006-291x(89)92427-3
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发表时间：
1989-02
影响因子：
3.1
通讯作者：
L. Packer;J. Maguire;R. Mehlhorn;E. Serbinova;V. Kagan
中科院分区：
文献类型：
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作者：
L. Packer;J. Maguire;R. Mehlhorn;E. Serbinova;V. Kagan
在大鼠肝微粒体和线粒体膜中表征了防止维生素 E 类似物 2,2,5,7,8-五甲基-6-羟基色烷 (PMC) 衍生的色满氧基自由基积累的酶依赖性机制。使用光化学（紫外线）或酶促（脂氧合酶和花生四烯酸）方法在膜中生成 PMC（色满氧基自由基）的自由基氧化产物，并通过 ESR 进行检测。底物（NADH 或 NADPH）可防止苯并二氢苯氧自由基的积累，直至底物完全消耗。在微粒体中，还原型谷胱甘肽增加了 NADPH 防止苯并二氢呋喃氧基自由基积累的功效，但在缺乏 NADPH 的情况下则没有效果。抗坏血酸还可以防止苯并二氢苯氧自由基的积累。结论是，大鼠肝微粒体和线粒体具有酶促和非酶促机制来减少苯并氧自由基。
Enzyme-dependent mechanisms which prevent accumulation of chromanoxyl radicals derived from the vitamin E analogue, 2,2,5,7,8-pentamethyl-6-hydroxycromane (PMC), were characterized in rat liver microsomal and mitochondrial membranes. The free radical oxidation product of PMC (chromanoxyl radical) was generated in membranes using either photochemical (uv light) or enzymatic (lipoxygenase and arachidonic acid) methods and detected by ESR. Substrates (NADH or NADPH) prevented accumulation of chromanoxyl radicals until the substrate was fully consumed. In microsomes, reduced glutathione increased the efficacy of NADPH in preventing the accumulation of the chromanoxyl radical, but was without effect in the absence of NADPH. Ascorbate also prevented accumulation of the chromanoxyl radical. It is concluded that rat liver microsomes and mitochondria have both enzymatic and non-enzymatic mechanisms for reducing chromanoxyl radicals.