Effects of the anti-androgen cyproterone acetate on mating behavior and seminal vesicle tissue in male rats.

The synthetic steroid cyproterone acetate (6-chloro-17-hydroxy-lα,2α-methylenepregna- 4,6-diene-3,20-dione acetate) exerts strong antiandrogenic properties with respect to the seminal vesicles, but not with respect to androgen dependent mating behavior in male rats. Gonadectomized, sexually experienced male rats were treated with 1) testosterone propionate (TP); 2) TP plus cyproterone acetate, or 3) oil for 3 weeks, and given 3 mating tests at weeklyintervals. The seminal vesicles of all males were removed after 2 weeks of treatment. The intensity of mating behavior declined progressively in the oil treated castrates but not the androgen or androgen plus anti-androgen treated males. The seminal vesicles of the oil treated and androgen plus anti-androgen treated rats regressed in comparison with the seminal vesicles of males treated only with testosterone. (Endocrinology 84:155, 1969)