title: [The biological role of estriol].
abstract: It was demonstrated on the uteri of women and guinea pigs that estriol (in vitro) possessed a marked affinity to the estradiol-binding system of human and guinea pig uteri; the activity of steroid-receptor interaction of estriol in vitro constituted 9.4% for guinea pigs and 17% for man in relation to the estradiol activity. Administration of estriol to guinea pigs in vivo in a dose of 0.25-0.5 mg led to a sharp reduction of the estradiol-binding capacity of the receptor system of the uterus. It is supposed that there existed a competitive relationship between estradiol and estriol for binding with the active centres of the receptor proteins of the uterus.
mesh_terms: D000818:Animals; D001667:Binding, Competitive; D004958:Estradiol / Q000378:metabolism; D004964:Estriol / Q000378:metabolism / Q000502:physiology*; D004967:Estrogens / Q000378:metabolism; D005260:Female; D006168:Guinea Pigs; D006801:Humans; D011956:Receptors, Cell Surface; D014599:Uterus / Q000378:metabolism*
chemical_list: D004967:Estrogens; D011956:Receptors, Cell Surface; D004958:Estradiol; D004964:Estriol
vernacular_title: K voprosu o biologicheskoĭ roli éstriola