HYPOCHLORITE-INDUCED PEROXIDATION OF PHOS PHOLIPID LIPOSOMES - A COMPARISON WITH PEROXIDATION IN THE FE2+ ASCORBATE SYSTEM/

The present study examined the kinetics of accumulation of lipid perox idation products in phosphatidylcholine liposomes incubated with hypoc hlorite (HOCl/OCl-) or with FeSO4 in the presence of ascorbate. The in cubation of liposomes with HOCl/OCl- led to the accumulation of primar y (lipid hydroperoxides and conjugated dienes) and secondary (TBA-reac tive substances) lipid peroxidation products identical to those genera ted in the presence of Fe2+/ascorbate. However the rate of the formati on of lipid peroxidation products as well as the gain in their amount were sufficiently higher (4-150 - fold and 3-6 - fold, respectively) i n the case of HOCl/OCl- - induced lipid peroxidation as compared to li pid peroxidation in the Fe2+/ascorbate system. The accumulation of lip id peroxidation products lasted until HOCl/OCl- was present in the rea ction mixture. The data obtained support our hypothesis that hypochlor ite produced by activated neutrophils and monocyte/macrophages may be reasonable for the initiation of lipid peroxidation in blood.