The imprinting of adult hepatic monoamine oxidase levels and androgen responsiveness by neonatal androgen.

Abstract

Monoamine oxidase (MAO) activity was measured in livers from male rats castrated neonatally and treated with hormones. MAO activity in the adult male, normally lower than that in the adult female, was elevated by neonatal castration to a level similar to that in the adult intact female. The increase in adult male MAO activity due to neonatal castration was not an artifact of adult androgen deprivation, since administration of testosterone propionate or dihydrotestosterone to the adult (castrated neonatally) for 7 days before sacrifice failed to reverse this increase. The administration of testosterone propionate or diethylstilbestrol to neonatal castrates on day 2 prevented the rise in MAO activity observed in the adult male after neonatal castration. The alterations in total MAO activity as a result of neonatal castration and hormone treatment were, in general, closely reflected by changes in levels of MAO type A. These results suggest that the sex-related differences in adult male and female MAO and the...