[Interaction of hypochlorite with hydroperoxides and other oxidation products of phosphatidylcholine liposomes].

The chemiluminescence in the presence of luminol has been used to measure the amount of hypochlorite and its reduction during the interaction with oxidized and non-oxidized liposomes from egg yolk phosphatidylcholine as well as with organic peroxides (tert-butylhydroperoxide, cumene hydroperoxide, di-tert-butylperoxide, tert-butylperbenzoate, di-benzoylperoxide), and epoxides (cis- and trans-2,3-epoxy-butane, cholesterol-5 alpha,6 alpha-epoxide, and cis-9,10-epoxystearic acid). Since hypochlorite did not react with the saturated phospholipid, dimyristoylphosphatidylcholine (DMPC), and the reduction of double bonds in egg yolk phosphatidylcholine liposomes occurred at the same rate in both oxidized and non-oxidized liposomes, it may be suggested that hypochlorite interacted precisely with LPO products. None of the epoxides tested in this study, similar to di-tert-butylperoxide, tert-butylperbenzoate, di-benzoylperoxide, incorporated into liposomes reacted with hypochlorite. In contrast, tert-butylhydroperoxide and cumene hydroperoxide effectively reacted with it. The data obtained suggest that epoxides, dialkyl-, diacyl-, and alkyl-acyl-peroxides are not involved in hypochlorite-induced LPO. At the same time, organic hydroperoxides commonly present in certain amounts in the biomembrane lipid phase in vivo may play a role lf an intermediate; its interaction with HOCl/OCl- gives rise to free radical formation followed by accumulation of LPO products.