title: Effect of treatment with estrogen conjugates on endogenous plasma steroids.
abstract: Plasma dehydroenpiandrosterone sulfate (DS), androstenedione (A2), estrone plus estradiol (E1+2) and estriol (E3) were measured in women treated with conjugated estrogens and controls. Plasma DS, A2, and E1+2 levels were higher in the premenopausal controls than in the untreated postmenopausal women; E3 levels were below the sensitivity of the assay. Estrogen conjugates, 1.25 mg or 2.5 mg daily, increased plasma E1+2 to levels similar to those in premenopausal untreated women, and E3 became readily assayable. A 0.625-mg dose increased the level of E3 without affecting E1+2; consequently, the plasma E3/E1+2 ratio was elevated. It is concluded that at the lowest dose 16 alpha-hydroxylase activity, perhaps by substrate induction, is sufficient for the exogenous esogenous estrogens to be largely metabolized to E3. Estrogen conjugates had no detectable effect on plasma DS or A2.
mesh_terms: D000735:Androstenedione / Q000097:blood; D003687:Dehydroepiandrosterone / Q000097:blood; D004958:Estradiol / Q000097:blood; D004964:Estriol / Q000097:blood; D004966:Estrogens, Conjugated (USP) / Q000494:pharmacology*; D004970:Estrone / Q000097:blood; D005260:Female; D012739:Gonadal Steroid Hormones / Q000097:blood*; D006801:Humans; D008593:Menopause; D039181:Steroid 16-alpha-Hydroxylase
chemical_list: D004966:Estrogens, Conjugated (USP); D012739:Gonadal Steroid Hormones; D004970:Estrone; D000735:Androstenedione; D003687:Dehydroepiandrosterone; D004958:Estradiol; D039181:Steroid 16-alpha-Hydroxylase; D004964:Estriol