Effect of a Single Prepubertal Injection of Testosterone Propionate on Later Reproductive Functions of the Female Golden Hamster

Female hamsters (Mesocricetus auratus) were injected sc with testosterone propionate (TP) (100 μg/g body weight) at 2, 4, 6, 12, or 20 days of age. At maturity, the females given TP at 4 days or later displayed normal 4- day vaginal, estrous and ovulatory cyclicity, whereas females given TP at 2 days were acyclic and their ovaries lacked corpora lutea. Apparently, the female cyclic type of hypothalamic control over pituitary gonadotropin secretion is normally determined on the 3rd or 4th day of age in this species. An unusual result of TP injection on the 4th or 6th day of age was that mating failed to interrupt 4-day cyclicity and to result in pregnancy. Evidently, coitus did not cause reflex release of pituitary luteotropic hormone in these normally cyclic females. In hamsters given TP at 12 or 20 days, as well as in controls, mating interrupted 4-day cyclicity and resulted in delivery of normal young. Injection of TP at 2 days prevented fusion of the vestibular walls, resulting in a common exterior opening of vaginal and urethral canals. Fusion occurred in all hamsters injected at later ages. Abscesses of the ovaries, tubes, or uterus were common in the 2-day group, less common in the 4-day group, and almost absent in the 6-day group. The onset of vaginal cyclicity (puberty) was delayed to a decree that was inversely related to the age injected; the delay was only a few days in the 20-day group. (Endocrinology85: 312, 1969)