Influence of Varying Proportions in Combinations of Estrone, Estradiol and Estriol on Biological Response

Abstract

Combinations of estrone + estriol; estrone + estradiol; estradiol + estriol were compared for effact on the immature rat uterus (Sherman strain). The interpretations were based on the data of the basis dose response curves which were established for immature female rats. Linear equations which were derived from the dose response data are as follows: [image] A synergistic effect was observed in all of the mixtures studied in the low dose level except with estrone + estradiol which showed it in the higher dose levels. A combination of estrone + estriol resulted in synergism in 3 out of the 5 mixtures studied up to a 5 [gamma] dose level. Estriol did not inhibit estrone activity in any of the mixtures. In the study of the 3 estradiol + estriol mixtures, there was evidence of inhibition in only one mixture (the 98.36% estriol + 1.64% estradiol mixture, where the estriol portion of the total dose was greater than 1.5[gamma]).