Studies on the physiology and biochemistry of mammalian epididymis: effect of flutamide, a nonsteroidal antiandrogen, on the epididymis of the rat.

The effect of flutamide (Sch 13521; 4'-nitro-3'-trifluoromethylisobutyranilide), a nonsteroidal antiandrogen, on male rat genital organs was studied. Administered at a dose of 25 mg/kg body weight daily for 30 days, flutamide caused a significant increase in the weight of the testis but had no effect on spermatogenesis and Leydig cell morphology. The secretory activity of the epididymis, as evidenced by the level of glycerylphosphoryl-choline and sialic acid, either remained unaffected or was stimulated. There was a significant decrease in seminal vesicle and ventral prostate weight and in the fructose content of the coagulating gland. The anti-androgen at the dose used did not affect the fertility of the rats. The significance of these findings is viewed in relation to the hypothesis of a differential threshold requirement of androgen for the epididymis and the accessory sex glands. The potentiality of antiandrogens as extragonadal antifertility agents in the male is discussed.