Effects of Gonadectomy on the Uptake of Polycyclic Hydrocarbons by Rat Liver Nuclei,DNA,and Histones

Summary

The effects of sex difference and of gonadectomy on the uptake of 7, 12-dimethylbenz[a]anthracene-³H and benz-[a]anthracene-³H by rat liver slices, hepatic DNA; and histones were studied. Liver slices from the intact male rat incorporated 7, 12 -dimethylbenz [a] anthracene-³H at a higher rate than benz[a]anthracene-³H. The uptake of 7,12-dimethylbenz[a]anthracene-³H by intact isolated liver nuclei increased after gonadectomy of the male rat, whereas the uptake of benz[a]anthracene-³H increased in liver nuclei from female rats after ovariectomy. Relatively small amounts of radioactive hydrocarbons were bound to DNA under the in vitro experimental conditions. Liver histones were found to bind radioactivity after incubation of liver slices with 7, 12-dimethylbenz[a]anthracene-³H and benz-[a]anthracene-³H. Gonadectomy led to an increase in the extent of binding of benz-[a]anthracene-³H to liver histones from both male and female rats. Uptake of 7, 12 -dimethylbenz [a] anthracene-³H by histones was increased only in liver of ovariectomized female rats.