The influence of testosterone administration on plasma prolactin levels in the neonatally androgenized (NA) female rat.

Neonatally androgenized (NA) female rats were ovariectomized (OVX) as adults and given 1 mg of testosterone propionate/day for 7 days and the plasma prolactin (PRL) pattern compared with NA intact animals and normal OVX animals given estrogen or TP. NA intact animals had elevated basal (morning values) and an attenuated afternoon surge when compared to normal estrogen-treated animals. Testosterone administration to normal animals induced an afternoon surge similar to that of normal estrogen-treated animals but the magnitude of the surge was less. Testosterone given to NA-OVX animals had little effect on either morning or afternoon PRL levels. The results suggest that in the NA rat the brain region involved in the conversion of testosterone to estrogen may be altered by neonatal androgen exposure.