Androgen Sterilization Produced by Intracerebral Implants of Testosterone in Neonatal Female Rats

Sterility and Delayed Vaginal Opening Following Electrolytic Lesions Placed Neonatally in the Medial Preoptic Area in Female Rats

“…A similar syndrome also occurs in adult rats following anterior neuronal deafferentation of the hypothalamus (Halasz and and in those having been administered with either androgens or estrogens during neonatal life (For reviews, Takewaki, 1962;Gorski, 1971;Arai, 1973). Androgen micropellets placed in the ventromedial-arcuate nucleus region of the hypothalamus (Nadler, 1972) or within a rather wide, undefinable area of the basal hypothalamus (Wagner et al, 1966;Hayashi and Gorski, 1974) of neonatal female rats were shown to induce anovulatory sterility in adulthood.…”

Further Evidence on the Intrahypothalamic Locus for Androgenization of Female Rats

“…3). A compari son of the latencies to onset of PVC, presumed to reflect the intensity of androgenic stimulation of the critical locus involved in the induction of PVC [Wagner et at., 1966;Nadler, 1971Nadler, , 1972, revealed a clear dichotomy between the animals with the VMH-ARC implants and the single animal with the anterior implant. The ages at onset of PVC for the former group of animals ranged from 35 to 77 days, whereas the value for the animal with the anterior implant was 130 days.…”

Intrahypothalamic implants of testosterone or dihydrotestosterone in neonatal female rats with reference to induction of sterility.

“…Micropellets of testosterone propionate (Wagner et al, 1966;Nadler, 1968 andHayashi and Gorski, 1974), estradiol (Hayashi, 1976a) or estradiol benzoate (Docke and Dorner, 1975) implanted into the hypothalamus of neonatal female rats also masculinize the brain while similar pellets placed subcutaneously were without effect. This effect of testosterone has been postulated to depend upon its conversion into estrogen in the brain of female rats, since aromatizing enzyme involved in the conversion is present in the neonatal hypothalamus (Naftolin et al, 1971 andWeisz and Gibbs, 1974) …”