Iron-catalyzed generation of pentane from irradiated erythrocyte membranes

Data presented here show that pentane is generated from human erthyrocyte membranes upon irradiation (800 Gy, cobalt-60) as measured by gas chromatography. Malondialdehyde production, measured by the thiobarbituric acid assay, accompanied pentane evolution. Pentane evolution can be modified by the addition of iron and various protective agents. Irradiation in the presence of 0.1 mN Fe2+ (ferrious ammonium sulfate) increased pentane formation from 9 to 34 pmol/mg membrane protein. Addition before irradiation of hyroxyl radical scavengers, such as benzoate (5mM), decreased pentane production from 34 to 14 pmol. Addition of WR-2721 resulted in a decrease in pentane to 15 pmol. Pentane production was greatly diminished by the presence of catalase or superoxide dismutase during irradiation. These studies suggest that oxygen radical species that are induced by ionizing radiation can affect mammalian cell membranes and this effect can be enhanced by iron, probably through catalysis of a Haber-Weiss type reaction