Effect of TSAA-291 on male reproductive tract and fertility of the rat.

Adult male rats were injected with TSAA-291 (16 beta-ethyl-17 beta-hydroxyestr-4-en-3-one), a steroidal antiandrogen, daily for 30 days at two doses, viz., 10.0 and 25.0 mg/kg. The treatment caused a dose-dependent reduction in the weights of testis, epididymis, and other accessory sex glands. In the animals that received the high dose, 50% of the rats showed spermatogenic arrest in about 20% of the seminiferous tubules and Leydig cell morphology was normal. The levels of glycerylphosphorylcholine and sialic acid were significantly reduced in the cauda epididymis of all the treated rats. There was a reduction in the number of motile spermatozoa in the cauda epididymis of rats treated with high dose of the antiandrogen. This was accompanied by a reduced number of females exhibiting spermatozoa in their vaginal smears. A combination treatment of the antiandrogen and androgen appears to be a promising approach for fertility regulation in the male.