Initiation of peroxidation of liposome membrane lipids by activated polymorphonuclear leukocytes

: The influence of active oxygen forms produced by zymosan-stimulated polymorphonuclear leukocytes (PMNL) on the initiation of liposome lipid peroxidation has been studied. It has been shown, by measuring the concentration of TBA-active products, that lipid peroxidation induced by PMNL stimulation occurs only in the presence of Fe-ADP. This fact demonstrates that OH'-radicals are responsible for the initiation of lipid peroxidation. Superoxide dismutase and catalase almost completely inhibited PMNL-stimulated peroxidation. The results obtained suggest that active oxygen forms that appear during PMNL stimulation can migrate at a considerable distance from the place of their origin, initiating peroxidation of cell membrane lipids and lipoproteins in the presence of Fe ions, which seems to underlie bacteriocidal and cytotoxic action of phagocytes.