Temporary sterility induced by intrascrotal deposition of silastic-polyvinylpyrrolidone-prostaglandin F2alpha tubes in the rabbit: effect on fetal survival after regain of fertility.

In male rabbits of proven fertility, the intrascrotal deposition of two Silastic-polyvinylpyrrolidone tubes containing 3 mg of prostaglandin F2alpha (PGF2alpha)/tube induced within 2 to 4 weeks temporary sterility which lasted for 10 to 14 weeks. Associated with induced sterility were reduction in testicular weight, increase in abnormal spermatozoa (8% to 78% versus 0 to 3.7%), and reduction in sperm motility along the reproductive tract and in the semen for a period of 6 to 7 weeks. During the period of temporary sterility the weight of the epididymis, the sexual drive, and semen volume remained unaltered. Normal fertility was associated with an increase in testicular weight, reduction in the proportion of abnormal sperm, and improved sperm motility. In addition to an altered spermatogenesis, the integrity of mature spermatozoa seemed to be severely affected after PGF2alpha treatment. The reduced number of viable young sired by males that recovered from temporary sterility (pregnancy wastage 35%) as compared with sham-treated controls (pregnancy wastage 3%) suggests that a small percentage of spermatozoa might still be defective at the time of testing. A longer waiting period might be needed to ensure a completely normal reproductive process.