THE POTENCY OF STILBESTROL IN THE IMMATURE FEMALE RAT

Abstract

SINCE THE DISCOVERY by Dodds, Golberg, Lawson, and Robinson (i) that stil-bestrol (diethylstilbestrol or 4:4′-dihydroxya-α:β-diethylstilbene) possesses a marked degree of estrogenic action, several papers have appeared reporting the relative potency of stilbestrol to estrone. A survey of the literature as shown in table i reveals great differences of results, chiefly perhaps due to the different methods em-ployed. In spayed mice, the two compounds wereequally active when injected sub-cutaneously, but stilbestrol was superior when given orally. In spayed rats the ratio of activity of stilbestrol to estrone varied from 1 to 5 by subcutaneous administration, and that by mouth ranged from 20 to 80. When immature rats were used, two groups of workers (15,16) obtained ratios as high as 15 to 16 following subcutaneous medica-tion. No difference between stilbestrol and estrone was demonstrated in immature ice by subcutaneous injection (14).