MALE ANTIFERTILITY COMPOUNDS: EFFICACY OF U-5897 IN PRIMATES ( <i>MACACAMULATTA</i> )

Abstract

Summary. Six, mature, male rhesus monkeys were given U-5897 (3-chloro-1,2-propanediol), 30·0 mg/kg/day, orally. Antifertility efficacy was assessed by comparing pre-treatment fertility (fourteen of twenty-eight matings fertile) with treatment fertility (one of twenty-four matings fertile). The dose was near the anticipated maximum tolerated level, therefore side effects were not unexpected. Three of the six experimental animals showed no detectable toxicity, death of two of the other three was apparently due to bone marrow depression. Sperm motility and morphology were not detectably altered in five of the six animals. Unaltered spermatogenesis and the short time required to attain efficacy in the present experiment imply a post-testicular site of action. Reversibility was demonstrated in three males by post-treatment matings (three of three matings fertile).