Androgenic Activity of C21 Steroids. ∗

Summary

Δ16-Dehydroprogesterone exhibited androgenic activity by direct application to the chick's comb. This steroid has approximately 6% of the activity of androsterone. Δ⁴-Pregnenetriol-17(α),20(β), 21-one-3-diacetate-20,21, and Δ⁴-Pregenenediol-17 (α), 21-dione-3,20-acetate-21 (compound “S” acetate, Resichstein) inhibited the growth of the combprobably by direct antagonism of endogenous androgens. 17(α)-Hydroxyprogesterone produced no consistent effect. By direct comb application 80 and 640 μg levels were without effect while the 320 μg dose produced a 29% comb ration increment which was statistically significant. When this steroid was injected subcutaneously at a dose of 100 μg a significant comb inhibition was observed.