The biphasic effect of calcium on lipid peroxidation.
Mechanisms underlying Ca2+ effects on lipid peroxidation (LPO) induced in liposomes (from egg yolk lecithin) and ufasomes (from linolenic acid and methyl linolenate) with the aid of an O2-(.) -generating system (Fe2+ + ascorbate) were studied. It was shown that stimulation of LPO by low Ca2+ concentrations (10(-6)-10(-5)M) was due to its ability to release Fe2+ ions bound to negatively charged (phosphate or carboxylic) lipid groups (of lecithin or linolenic acid), thus increasing the concentration of catalytically active Fe2+. The inhibitory effect of high Ca2+ concentrations was caused by its interaction with superoxide anion radicals and was not observed in LPO systems independent of O2- generation (e.g., Fe2+ + cumol hydroperoxide).
Babizhayev
M A
MA
Moscow Helmholtz Research Institute of Eye Diseases, USSR.
D002118:Calcium / Q000494:pharmacology*; D005290:Ferric Compounds / Q000494:pharmacology; D007700:Kinetics; D008054:Lipid Peroxides / Q000096:biosynthesis*; D008081:Liposomes / Q000378:metabolism; D008433:Mathematics; D008954:Models, Biological
D005290:Ferric Compounds; D008054:Lipid Peroxides; D008081:Liposomes; D002118:Calcium