Male antifertility: An approach

Abstract

Experimental data in the rat is presented for an approach to male fertility regulation. The concept involves administration of an anti-gonadotropic steroid plus a replacement androgen to inhibit spermatogenesis and to maintain normal secondary sex characteristics. A model system utilizing the adult male rat is described. FSH and LH concentrations in the plasma or serum increase 8–10 fold in response to castration. Secondary accessory organs atrophy significantly within 10 days following surgery. The near optimal replacement dosage of testosterone propionate (TP) in castrated male rats was 40 μg 100 g body weight day . Provera® ( 300 μg 100 g BW day ), an antigonadotropic steroid, when administered to castrate males for 10 days decreased plasma LH and FSH concentrations to values observed in intact rats. TP ( 40 μg 100 g BW day ) in intact males exerted an effect on accessory organs by the fifth day of treatment. The effect was still increasing after 10 days of treatment. Provera, in intact rats, inhibited accessory organ weights by the fifth day of treatment and no additional inhibition was detected after 10 days. A combination of Provera and TP in the intact male did not significantly affect accessory organ weights after 10 days treatment; however, testicular weights were significantly inhibited. In all animals treated with Provera, significant adrenal atrophy was evident.