Free Radical Damage and Lipid Peroxidation

This chapter describes essentials of the chemistry of lipid peroxidation and the role of iron in initiation and propagation of lipid peroxidation. It presents major cellular antioxidant mechanisms. The mechanisms through which iron, oxygen, and certain hepatotoxins effect tissue damage frequently involve formation of intermediate free-radical species and the initiation of lipid peroxidation. Within the context of the study of basic mechanisms, lipid peroxidation has attracted a great deal of attention. This is due in part to the wide range of xenobiotics known to cause peroxidative decomposition of liver lipids and to the fact that lipid peroxidation is so destructive for biological membranes. Thus, once lipid peroxidation is initiated, the process can be propagated via autocatalysis, which is dependent not only on oxygen, but on metal catalyzed decomposition of transiently appearing lipid hydroperoxides. For the toxigenic aryl halides and for allyl alcohol it is doubtful whether the glutathione depletion alone is responsible for the onset of the massive lipid peroxidation.