A sex related difference in gonadotrophin response to castration in the rat.

Castration at birth, or at 25 days of age, increased plasma gonadotrophin levels in adult male and female rats. In the females, the effects of castration at 25 days of age or at birth were essentially the same. In the males castrated at 25 days of age, plasma gonadotrophin levels were less than for those castrated at birth. These results indicate a sex-related difference in the gonadotrophin response to castration.