Abstract
Phosphatidylcholine was irradiated in the state of a film or liposome with gamma-rays or electron beams, and the amount of peroxide was determined to compare the effects of the two types of radiation. The amounts of peroxide formed in both the film and liposome with gamma-rays were significantly larger than those with electron beams, when the samples were irradiated at the same dose. Proteins such as bacteriorhodopsin reduced the degree of peroxide formation in liposome, and the effect of gamma-rays was much larger than that of electron beams, even in the presence of protein. The results of the present investigation indicate that the effects of gamma-rays on peroxide formation in phosphatidylcholine were significantly larger than those of electron beams, irrespective of the state of the lipid.