Vaginal contraceptive activity of hyaluronidase and cyclooxygenase (prostaglandin synthetase) inhibitors in the rabbit.

Seven inhibitors of the sperm enzyme hyaluronidase were tested at nonspermicidal concentrations for their vaginal contraceptive activity in rabbits. Five of these compounds are marketed antiinflammatory agents and the other two were synthesized. Most of the agents showed contraceptive activity. Of the antiinflammatory agents, phenylbutazone and oxyphenbutazone were particularly potent. Besides being hyaluronidase inhibitors, these compounds are also cyclooxygenase (prostaglandin synthetase) inhibitors; based on other in vitro data, their primary effect on spermatozoa is probably by the inhibition of that enzyme.