The Effects of 17β-Estradiol and Medroxyprogesterone Acetate Alone and in Combination with α-Chlorohydrin on Reproductive Function in the Male Rat

Experiments were designed to test the effects of 17β-estradiol and medroxyprogesterone acetate (Provera) alone and in combination with α-chlorohydrin on spermatogenesis, accessory organ weights, mating behavior and fertility in male rats. Fertility was not impaired by daily injections of a subminimal dose of α-chlorohydrin alone or in combination with 1 mg Provera (one injection per 5 days for 25 days). The total number of implantation sites was significantly reduced in females mated with males receiving 1 mg 17β-estradiol daily for 5 days and combined treatment with 0.6 mg α-chlorohydrin/rat/day enhanced this antifertility effect. The 25-day treatment of 17β-estradiol impaired spermatogenesis, reduced the number of spermatozoa in the epididymis and ductus deferens and prevented further increase in body weight but the effects were reversed and fertility was regained within 10 weeks after the end of treatment.