Inhibitory effects of centrally acting drugs on the neonatal imprinting of sex differences in the hepatic metabolism of a dimethylated epoxide in the rat.

The effects of the neonatal administration of reserpine, chlorpromazine, phenobarbitone and morphine on the development of sex differences in hepatic drug metabolism in the rat have been investigated. Treatment of neonatal male rats with reserpine or chlorpromazine for the first two weeks post-partum significantly inhibited the development of sex differences in drug metabolism in adult life. Similar treatment of neonatal female rats with reserpine or chlorpromazine had no effect on the development of hepatic drug metabolism in adulthood. Morphine or phenobarbitone treatment of neonatal rats of either sex had no effect on the development of sex differences in hepatic drug metabolism in adult life.