Contraceptive effects of intravaginal application of acrosin and hyaluronidase inhibitors in rabbit.

Eight single-drug and combinations of two-drug treatments were used to study the contraceptive efficacy of the intravaginal application of acrosin inhibitors (TLCK; NPGB) and hyaluronidase inhibitors (Compound 53D/k; Phosphorylated hesperidin) in the rabbit. Drug concentrations were selected so that they did not inhibit rabbit sperm motility upon incubation at 37 degrees C for 30 minutes. In the first series, the drugs were added to semen before artificial insemination; in the second series, the drugs were administered intravaginally before artificial insemination with untreated rabbit semen. The data show that these drugs are highly effective intravaginal contraceptives in the rabbit. The data suggest that this is a specific inhibitory effect on fertilization since the drug concentrations used did not affect sperm motility.