Antireproductive Effects of Tamoxifien when Applied Locally to the Epididynis of Rats

Abstract

This study investigated the effects of tamoxifen, an oestrogen receptor antagonist on fertility of male rats. This was done by applying the drug directly to the epididymis through implantation of silastic rods containing 50% of drug (day 0) and subjecting these rats to serial mating on day 3, and then approximately at weekly intervals upto day 70. The tamoxifen treatment caused significant impairment in sperm numbers in the ejaculate possibly via spermatogenic arrest (between days 21-42), fertility index (on days 28 and 35), number of uterine implants (on day 35) orquantal pregnancy (on day 35) and a significant elevation in pre-implantation loss (on day 35). On the other hand, tamoxifen treatment had no significant effects on libido and in post-implantation loss. It is concluded that tamoxifen mediated its antifertility action mainly through production of oligozoospermic ejaculates possibly via the inhibition of Sertoli cell function.