The effect of a new antiandrogenic steroid, 6-chloro-17-HYDROXY-1α, 2α-methylenepregna-4,6-diene-3,20-dione acetate (cyproterone acetate) on the sebaceous glands of mice.

The effect of a new antiandrogenic steroid, 6-chloro-17-hydroxy-la,2a-methylenepregna-4,6-diene-3,20-dione acetate (cyproterone acetate) on sebaceous glands of mature male mice as well as mature castrated mice treated with testosterone propionate has been studied qualitatively and quantitatively. A dosage of 1 mg cyproterone acetate every second day for a period of 4 weeks induces a reduction of the relative total sebaceous gland volume of about 80% in intact mice. The stimulant effect of 0.5 mg testosterone propionate every second day and over a period of 4 weeks on sebaceous glands is inhibited by the simultaneous treatment with 1 mg cyproterone acetate every second day. The effect of cyproterone acetate produces a decrease of the number of sebaceous gland alveoli, elicits a reduction of the number of cells per alveolus as well as a decline in cell size. The thickness of the epidermis was decreased in the animals treated with cyproterone acetate. The mechanism of action of this antiandrogen has been explained by a competitive testosterone antagonism since, in contrast to estrogens, the stimulant effect of exogenous testosterone on sebaceous glands is also inhibited.