Effect of Sex Hormones on Lipid Peroxidation in Rat Liver

The role of sex homones in hepatic lipid peroxidation, and in hepatic adehyde odidase and xanthine oxidase activites were investigated using rat liver homogenates. It was observed that male rt had a significantly greater content of malondialdehyde in liver than female. Among the sex hormones tested, estradiol, one of female hormones, markedly inhibited the formation of lipid peroxides in liver tissues in vitro. Especially, the inhibitory effect of estradiol appeared more remarkably in Fe-induced lipid peroxidation. The hepatic xanthine oxidase activity was decreased about 15% by $10\;^6\;M$ estradiol, wherease, the adehyde oxidase activity was almost completely disappeared at the same concentration of estradiol. It implies that sex differences in lipid peroxidation is attributed to the suppression of radical generating system by estradiol.