EFFECT OF SOME TRIPHENYLETHYLENES ON OESTRADIOL BINDING IN VITRO TO MACROMOLECULES FROM UTERUS AND ANTERIOR PITUITARY

Abstract

SUMMARY The effects of a series of triphenylethylenes (I.C.I. 46,474, I.C.I. 47,699 and clomiphene isomers A and B) on oestradiol binding to receptors from rat, rabbit and mouse uteri and rat anterior pituitary were studied. Binding of oestradiol to receptors from uteri was inhibited competitively by I.C.I. 46,474. Receptors from uteri of the three species and from rat anterior pituitary have very similar affinities for oestradiol and the four triphenylethylenes. The order of activity of the triphenylethylenes as inhibitors of oestradiol binding is: clomiphene B > I.C.I. 46,474 > I.C.I. 47,699 > clomiphene A. Some correlations are made with the activity of the compounds in vivo.