Effects of diethylstilbestrol and testosterone propionate implanted in the hypothalamus on spermatogenesis in rats.

Small quantities of diethylstilbestrol and testosterone proprionate were implanted into the hypothalamic arcuate nucleus of male rats of the Wistar-Imamichi strain at 43 days of age. The animals were sacrificed at 64 or 76 days of age. Diethylstilbestrol suppressed the development of all genital organs and disturbed spermatogenesis. The damage was found to have recovered slightly in rats sacrificed at 76 days of age. Testosterone propionate was also effective for the atrophy of some genital organs. Its influence was not so severe as that of diethylstilbestrol. It extinguished almost completely 33 days after implantation. On the contrary, the numbers of spermatogonia and spermatocytes per cross section of the seminiferous tubule were smaller at 76 days than at 64 days of age. The diameter of the seminiferous tubule in the rat implanted with testosterone propionate was longer at 76 days than at 64 days of age. Therefore, the tubular diameter did not always represent the quantity or quality of spermatogenesis. The results also suggested that spermatogenesis might have been disturbed in some of the rats in which androgen was considered to be secreted almost normally.