LIPID OXIDATION IN BILAYER LIPOSOMES INDUCED BY RADICALS FROM THE SURROUNDING WATER PHASES

Some features of the radiation chemistry of organized assemblies were studied in aqueous dispersions of small unilamellar vesicles of egg yo lk lecithin. The kinetics for the reaction of OH radicals with the bil ayer was determined by pulse radiolysis. The conversion of OH radicals into N-3 radicals results in a remarkable reduction of the radiolysis of the hydrophylic part of the phospholipid and in an enhanced degrad ation of the most radiosensitive group of polyunsaturated fatty acid r esidues. The transverse proton relaxation of the choline head group is very sensitive to the radical attack on the bilayer.