The mechanism of the hypochlorite-induced lipid peroxidation.
The article reviews data related to the role of exogenic hypochlorite (HOCl/OCl-) and hypochlorite produced by myeloperoxidase catalysis in initiation of lipid peroxidation (LPO) in phospholipid membranes and human blood lipoproteins (LP). It has been shown that HOCl/OCl- promotes free radical lipid oxidation in liposomes and LP that is followed by the formation of LPO products; hydroperoxides, conjugated dienes, TBARS, and fluorescent products. Water soluble reactive substances (.O2-, H2O2, Fe2+) which can be present in the reaction mixture as a dopant are not the source of free radicals and do not participate in HOCl/OCl(-)-induced LPO at the initiation step. The main reaction of HOCl/OCl- with unsaturated lipid is probably the generation of chlorohydrins. However, this reaction is not accompanied by generation of free radicals and LPO. HOCl/OCl- reacts efficiently with TBARS of aldehydic nature. It is likely that the reaction proceeds without the participation of free radicals. Among the compounds of a peroxide nature (hydro-, dialkyl-, diacyl-, alkyl-acyl-peroxide groups and epoxides) only hydroperoxides react with HOCl/OCl-. This reaction is accompanied by the production of free radicals (but not singlet oxygen), probably alkoxyl radicals, which may play a role in the initiation of HOCl/OCl(-)-induced LPO.
Panasenko
O M
OM
Research Institute of Physico-Chemical Medicine, Moscow, Russia. panasenko@glas.apc.org
D000818:Animals; D002384:Catalysis; D005609:Free Radicals / Q000378:metabolism; D006801:Humans; D006997:Hypochlorous Acid / Q000378:metabolism* / Q000494:pharmacology*; D015227:Lipid Peroxidation / Q000187:drug effects* / Q000502:physiology; D008074:Lipoproteins / Q000097:blood; D008563:Membrane Lipids / Q000378:metabolism; D008954:Models, Biological; D009195:Peroxidase / Q000378:metabolism*; D010743:Phospholipids / Q000378:metabolism
D005609:Free Radicals; D008074:Lipoproteins; D008563:Membrane Lipids; D010743:Phospholipids; D006997:Hypochlorous Acid; D009195:Peroxidase