Influence of testosterone propionate administered neonatally on puberty and bisexual behavior in female hamsters.

Abstract

Female hamsters were treated with oil, 3-/ig., 30-/ig., or 300-yug. testosterone propionate (TP) as neonates. Neonatal TP treatment delayed the onset of puberty by 4.5 days to an age near that previously reported for the male hamster. In addition, neonatal TP altered genital morphology, induced the capacity for mounting behavior, and at the highest dosage, disrupted the ability to bear and rear young. Vaginal and behavioral estrous cycles, however, were not influenced by neonatal TP. In a second experiment, 600-/*g. TP administered neonatally blocked estrous cyclicity, but did not eliminate the capacity to display feminine sexual behavior. These results imply that "mascuhnization" and "defeminization" are separate aspects of neurobehavioral sexual differentiation, and that "defeminization" includes several independent physiological processes.

Differential influence of stereoisomers of estradiol on sexual behavior of female hamsters.

“…The present data are generally consistent with the demonstration that in the hamster, masculinization is more easily produced by neonatal hormone treatment than is defeminization and that defeminization consists of several independent component responses, each differentially sensitive to hormone dosage (DeBold & Whalen, 1975;Whitsett & Vandenbergh, 1975). Masculinization, as measured by induction of the ability to display mounting behavior, was produced readily by neonatal treatment with £2-17/3.…”

“…Each female was paired with a proven stud male for 3 min per day or until the female exhibited lordosis or fighting occurred. Details of the procedures for vaginal examination and behavioral testing are provided in Whitsett and Vandenbergh (1975).…”

“…At the end of the experiment the neonatally treated females were examined for genital abnormalities. Estradiol-induced aberrations did not follow the relatively clear-cut patterns observed in TP-treated females by Whitsett and Vandenbergh (1975). Three measurements were taken: clitoral area (length X width as measured on anterior side), length of urethral opening, and urethral-vaginal distance.…”

Physical and behavioral aspects of sexual maturation in male golden hamsters.

“…Several studies support the existence of such a sex difference in the hamster (Diamond, Mast, & Yanagimachi, 1974;Vandenbergh, 1971b). Whitsett and Vandenbergh (1975) produced evidence that this difference is regulated by hormonal conditions earlier in life. The administration of testosterone propionate to neonatal female hamsters delayed the onset of estrous cyclicity by several days to an age similar to that previously reported for the attainment of sexual maturity in males.…”

Effect of Neonatal Intrahypothalamic Testosterone Implants on Cyclicity and Adult Sexual Behavior in the Female Hamster

“…It is unclear why mounting behavior was not facilitated by neonatal subcutaneous injections of TP in this study, since other investigators [40,41] found significant increases in mounting with similar doses of TP given to newborn fe male hamsters. This discrepancy could possibly be due to the fact that in both of the other studies the steroid was ad ministered within the first 48 postnatal hours, whereas in this experiment the hamsters were more than 48 h old when given the TP injections.…”