Effect of estrogen given during various periods of prepuberal life on the sexual behavior of rats

Abstract

Male and female rats gonadectomized on the day of birth received injections of estradiol benzoate (EB) every other day for 10 days beginning at 2, 12, 22, or 32 days of age, or they received no EB. Females were further divided as to whether, at 3 days of age, they were injected with oil vehicle, 5 micrograms testosterone propionate (TP), or 50 micrograms TP. Female behavior was evaluated in response to injected EB and progesterone beginning at 100 days of age, and male behavior was evaluated in response to TP injections beginning at 150 days of age. As frequently reported, TP and EB injected during neonatal life significantly suppressed female behavior in both females and neonatally castrated males. EB given later in prepuberal life was found to complexly influence sexual behavior at adulthood. The findings are discussed with respect to suggestions that ovarian tenancy during prepuberal life can affect the development of female sexual behavior. Also considered is the possibility that changes in the capacity of the developing brain to aromatize androgens into estrogens might account for the finding in that EB, unlike TP, injected after 10 days of age, could suppress female sexual behavior.