[Nature of the recognition system of uterine cell plasma membranes for estradiol]

The interaction of 3H-estradiol and 3H-corticosterone with plasmatic membranes of the rat uterine cells was investigated. It was revealed that accumulation of estradiol in plasmatic membranes was conditioned by two processes: by the binding with highly specific glycoprotein membrane structures and by estrogen diffusion into the lipid membrane phase. At the same time, accumulation of corticosterone is determined exclusively by its penetration into the lipid matrix of plasmatic membranes of the rat uterine cells.