Comparison of the antispermatogenic effects of a new D-homo-steroid and testosterone in rabbits

In comparison to testosterone, 18 beta-hydroxy-18 alpha-methyl-16 alpha-methylene-D-homo-5 alpha-androstane-3-one (D-homo-S) shows more pronounced anti-gonadotrophic than androgenic properties in rats. The present study was initiated in rabbits to investigate the potential of D-homo-S to suppress spermatogenesis. D-homo-S in sesame oil was administered at the doses of 0.1 (DI), 3 (D II) or 10 mg (D III) per rabbit each day for 8 weeks. During treatment serum testosterone, sperm concentration and quality of sperm motility decreased, whereas sex drive, semen volume and seminal plasma concentrations of fructose and zinc were not changed in any of the groups. Testicular weight and intratesticular testosterone concentration decreased significantly in groups D II and D III, while weights of accessory sex glands increased in those groups. Testosterone in the same dose regimen did not suppress sperm count, motility or serum testosterone, however, seminal plasma zinc concentration in group T III and fructose in group TI increased. Testicular weight and intratesticular testosterone concentration decreased in group TIII only. On the other hand, the weight of the accessory sex glands increased in the same group. In conclusion, D-homo-S suppresses spermatogenesis and increases accessory sex gland weights at doses, when testosterone is still ineffective. Thus, in rabbits D-homo-S appears to be a more potent androgen than testosterone but a dissociation between antigonadotrophic and androgenic properties could not be observed.