Effect Of Local Epididymal Levonorgestrel On The Fertilizing Ability Of Male Rat, A Model For Post-Testicular Contraception

A thin levonorgestrel-silicone layer was applied on the capsule of the cauda epididymis of male rats to study a model for post-testicular male contraception. The effect of different levonorgestrel doses on the fertility of males was tested with fertile females. The time-dependent influence of a standard dose of levonorgestrel on serum LH and on testicular histology was estimated. Among the males tested, there was a group of animals where successful contraception with local application of levonorgestrel-silicone membrane was obtained. Sexual behavior was normal and the spermatogenesis was functioning, but the sperm were infertile. Although further research is needed to estimate adequate dose and strength of levonorgastrel in silicone matrix, this study shows that post-testicular contraception is possible to achieve. CONTRACEPTION 2000;61: 401-406 (C) 2000 Elsevier Science Inc. All rights reserved.