THE COMPARATIVE ESTROGENIC POTENCY OF DIETHYL STILBESTROL, ESTRONE, ESTRADIOL AND ESTRIOL

Abstract

The oral adm. of graded doses of stilbestrol to rats and mice showed a dose-% response almost identical to that obtained by Coward and Burn and D''Amour and Gustavson for natural estrogens. Assayed by oral adm. to spayed adult mice estrone, estradiol, and estriol were respectively, 1/65, 1/20 and 1/10 as effective as stilbestrol. In rats estrone was 1/80, estradiol 1/65 and estriol 1/30 as effective as stilbestrol. When assayed on spayed adult mice and rats by subcut. inj. stilbestrol had about the same order of potency as estrone. By the oral route in mice stilbestrol is \ as effec-tive as estrone subcut. In rats, however, the effectiveness is approx. the same when compared in this manner.