Iron Redox Reactions and Lipid Peroxidation
The peroxidation of membrane polyunsaturated fatty acids is usually proposed to be initiated by the hydroxyl radical generated by the Haber-Weiss reaction, or a superoxide-driven Fenton reaction. However, it has been impossible to show that either liver microsomal NADPH-dependent lipid peroxidation or xanthine oxidase-dependent lipid peroxidation involves the hydroxyl radical, despite the fact that the hydroxyl radical is quite capable of promoting lipid peroxidation1. Catalase has no effect on microsomal lipid peroxidation2 and xanthine oxidase-dependent lipid peroxidation is often stimulated by catalase1. Lipid peroxidation can be initiated simply by the addition of Fe(II). If the iron does not oxidize rapidly, lipid peroxidation only occurs after a lag period. The lag is not affected by either SOD or catalase but can be abolished by the addition of Fe(III) or oxidants that catalyze oxidation of a portion of the Fe(II). These and other data led us to propose that lipid peroxidation is catalyzed by some type of Fe(II):Fe(III) complex3,4.
KeywordsLipid Peroxidation Xanthine Oxidase Iron Reduction Microsomal Lipid Peroxidation Phospholipid Liposome
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- 4.G. Minotti and S.D. Aust, The requirement for iron (III) in the initiation of lipid peroxidation by iron (II) and hydrogen peroxide, J. Biol. Chem. 262:1098 (1986).Google Scholar