Abstract: | The effect of the oral administration of megestrol acetate (MA; 17 alpha-acetoxy-6-dehydro-6-methylprogesterone) for 30 days at a dose of 40 mg/kg body weight/day on the genital organs and fertility of male rats was studied. MA had no effect on spermatogenesis or the fertility of the animals. However, the weights of the genital organs were significantly reduced (p less than .05) and pituitary gonadotropin levels were significantly increased (p less than .01). These alterations were reversed after cessation of treatment. Although MA and testosterone propionate each increase seminal vesicle weight, their combined administration significantly decreased seminal vesicle and ventral prostate weight (p less than .01). The significance of the results are discussed. |