[Inhibition of the uterine binding of estrogens by unsaturated fatty acids in immature female rats].

We demonstrate that the interactions between the uterine cytosol proteins of 24 day old Rats and estradiol-17 beta (E2) are significantly influenced by physiological concentrations of non esterified fatty acids (2. 10(-4)M). We show that the specific binding of the hormone to the 8S uterine receptor, is markedly inhibited (50-80%) by the unsaturated fatty acids. The observed inhibition is a function both of acid dose and acid unsaturation degree. The polyunsaturated arachidonic and docosahexaenoic acids are the strongest inhibitors, whereas the saturated palmitic and stearic acids do not displace the E2 from the 8S receptor.