title: [Studies on estradiol dehydrogenase activity in the human uterine endometrium].
abstract: Kinetics of estradiol dehydrogenase (E2DH) activity and the in vitro effects of progesterone (P) and synthetic steroids on E2DH activity were investigated in human normal endometrium and endometrial carcinoma. In proliferative and secretory endometrium and endometrial carcinoma, E2DH activities were 1.5 +/- 0.2, 10.1 +/- 1.1 and 1.2 +/- 0.1 nmol/mg protein/h (mean +/- SEM), Km was 2.3 microM, and Vmax were 0.20, 1.7 and 0.14 nmol/mg protein/10 min, respectively. Culturing proliferative endometria with progestogens resulted in a time- and dose-dependent stimulation of E2DH activity up to 72 h and 10(-6) M, respectively. Medroxyprogesterone acetate had the highest effect to stimulate E2DH activity among the steroids investigated. Chlormadinone acetate, norethindrone, P and R2323 were also effective. However, danazol, lynestrenol and E2 had negligible effect. Histological examination showed that progestogens caused early secretory change in the proliferative endometrium. These results indicate that the progestational activity is responsible for the elevation of E2DH activity in proliferative endometrium and that the extent to which each steroid increases E2DH activity may correlate with its local progestational activity. In the endometrial carcinoma, progestogens also stimulated E2DH activity in seven cases out of nine during culture for 48 h, but the elevation was lower than that in the proliferative endometrium.
mesh_terms: D015067:17-Hydroxysteroid Dehydrogenases / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D004717:Endometrium / Q000187:drug effects / Q000201:enzymology*; D004960:Estradiol Dehydrogenases / Q000378:metabolism*; D005260:Female; D006728:Hormones / Q000494:pharmacology; D006801:Humans; D066298:In Vitro Techniques; D008525:Medroxyprogesterone / Q000031:analogs & derivatives / Q000494:pharmacology; D017258:Medroxyprogesterone Acetate; D011372:Progestins / Q000494:pharmacology; D014594:Uterine Neoplasms / Q000201:enzymology
chemical_list: D006728:Hormones; D011372:Progestins; D017258:Medroxyprogesterone Acetate; D015067:17-Hydroxysteroid Dehydrogenases; D004960:Estradiol Dehydrogenases; D008525:Medroxyprogesterone