2-hydroxyestradiol and 2-hydroxyestriol
2-hydroxyestradiol has been researched along with 2-hydroxyestriol* in 6 studies
Other Studies
6 other study(ies) available for 2-hydroxyestradiol and 2-hydroxyestriol
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Treatment with an inhibitor of catechol-O-methyltransferase activity reduces preterm birth and impedes cervical resistance to stretch in pregnant rats.
Catechol-O-methyltransferase (COMT) enzyme catalyzes the methylation of the 2- or 4-hydroxyestrogens to 2- or 4-methoxyestrogens. Both the hydroxyestrogens and methoxyestrogens have been shown to block or enhance the effects of estrogen respectively. Our objective was to investigate the potential role of COMT in parturition and cervical ripening using a rat model. Immunohistochemistry was conducted to detect and localize the COMT protein in rat uterine tissues during pregnancy. We measured the longitudinal changes in urinary 2-hydroxyestrogen before, during, and after pregnancy in rats. Animal studies were conducted to determine the effect of treatment with a selective COMT inhibitor on (1) mifepristone-induced preterm birth and (2) cervical resistance to stretch in pregnant rats. The intensity of staining for the COMT protein differed within the luminal epithelium, uterine gland epithelium, endometrium, and myometrium during pregnancy. Levels of staining for the COMT protein in rat myometrium were highest on day 1 and lowest on days 8 and 13, but high levels returned by days 16 and 19 of pregnancy. The levels of urinary 2-hydroxyestrogen gradually increased in the first 2 weeks of pregnancy, peaked from days 16 to 18 of pregnancy, and then gradually returned to pre-pregnancy levels after delivery. The percentage of pups retained in the uterus of pregnant rats treated with both mifepristone and COMT inhibitor (48 +/- 15%) was significantly higher (P < 0.05) when compared with the value of pregnant rats treated with mifepristone alone (12 +/- 4%). The resistance to stretch was significantly higher (P < 0.05) in cervical tissues from the pregnant rats treated with COMT inhibitor (0.28) when compared with cervical tissues taken from rats treated with vehicle control (0.18). Modulation of COMT activity may play a role in the regulation of myometrial contractility and cervical ripening during pregnancy. Topics: Animals; Benzophenones; Biomarkers; Catechol O-Methyltransferase; Catechol O-Methyltransferase Inhibitors; Cervical Ripening; Cervix Uteri; Estradiol; Estriol; Female; Hydroxyestrones; Immunohistochemistry; In Vitro Techniques; Mifepristone; Models, Animal; Obstetric Labor, Premature; Pregnancy; Rats; Rats, Sprague-Dawley | 2007 |
Catechol estrogens are more potent antioxidants than estrogens for the Cu(2+)-catalyzed oxidation of low or high density lipoprotein: antioxidative effects of steroids on lipoproteins.
In order to clarify the mechanism of antiatherogenic action of several steroids such as estrogens, dehydroepiandrosterone (DHEA) and dexamethasone, we investigated the effects of various steroids on the copper (Cu2+)-catalyzed oxidation of low density lipoprotein (LDL) or high density lipoprotein (HDL) in 0.15 M NaCl by measuring thiobarbituric acid-reactive substances (TBARS). At a concentration of 10(-5) M, estrogens strongly protected against LDL oxidation by 0.5 microM Cu2+ in the following order of inhibition: estradiol (E2) (75%), estrone (E1) (35%) and estriol (E3) (30%). However, the corresponding metabolites of these estrogens, the catechol estrogens, had an even more protective effect on LDL oxidation by 0.5 microM Cu2+ in the following order of inhibition: 2-hydroxyestradiol (2-OHE2) (98%), 2-OHE1 (97%) and 2-OHE3 (96%). E2 and 2-OHE2 from 10(-7) M to 10(-5) M inhibited LDL oxidation in a dose-dependent manner, with a more marked effect for oxidation by 0.1 microM Cu2+ than by 0.5 microM Cu2+. 10(-5) M dexamethasone produced a slight (10%) but significant inhibition of LDL oxidation by 0.5 microM Cu2+. In addition, the estrogens and catechol estrogens were also effective in protecting against HDL oxidation by 0.5 microM Cu2+. Other steroids including DHEA and DHEA-sulfate had no antioxidative effects on either LDL or HDL in this system. These results indicate that estrogens and their metabolites, the catechol estrogens, exert antioxidative effects on both LDL and HDL. The catechol estrogens may be more important antioxidants than estrogens for both LDL and HDL.(ABSTRACT TRUNCATED AT 250 WORDS) Topics: Antioxidants; Copper; Estradiol; Estriol; Estrogens; Estrogens, Catechol; Estrone; Humans; Hydroxyestrones; Lipid Peroxidation; Lipoproteins, HDL; Lipoproteins, LDL; Male; Oxidation-Reduction; Thiobarbituric Acid Reactive Substances | 1994 |
Novel and potent biological antioxidants on membrane phospholipid peroxidation: 2-hydroxy estrone and 2-hydroxy estradiol.
Catechol estrogens, 2-hydroxy estrone, 2-hydroxy estradiol and 2-hydroxy estriol, were tested as possible antioxidants of phospholipid peroxidation induced by Fe3+-ADP-adriamycin, using phospholipid liposomes as lipid source and alpha-tocopherol or other steroids as reference compounds. The parameters of antioxidant activities were: elongation of induction period, inhibition of O2 consumption required for lipid peroxidation and inhibition of peroxidative cleavage of unsaturated phospholipid. Of the tested compounds, 2-hydroxy estradiol or 2-hydroxy estrone had more potent activity than that of tocopherol. Topics: Adenosine Diphosphate; Animals; Antioxidants; Doxorubicin; Estradiol; Estriol; Estrone; Ferric Compounds; Hydroxyestrones; Kinetics; Lipid Peroxides; Liposomes; Microsomes, Liver; Oxygen Consumption; Phospholipids; Rats; Vitamin E | 1987 |
Effect of catechol estrogens and estriol on the induction of uterine peroxidase.
Topics: Animals; Catechols; Enzyme Induction; Estradiol; Estriol; Estrogens; Estrogens, Catechol; Female; Hydroxyestrones; Peroxidases; Rats; Structure-Activity Relationship; Uterus | 1980 |
Comparative properties of the catechol estrogens, I: methylation by catechol-O-methyltransferase and binding to cytosol estrogen receptors.
Five catechol estrogens and two 2-methoxyestrogens were compared for their relative affinity of binding to hypothalamic, pituitary, and uterine cytosol estrogen receptors; and for the kinetics of the catechols' methylation by hepatic catechol-0-methyltransferase. All of the catechol estrogens tested have similar Km's for 0-methylation (9-14 muM). Estrogen receptor affinities, however, differ widely. In hypothalamus, for example, where estradiol-17 beta has a Kd of 0.039 +/- 0.008 nanomolar, 4-hydroxyestradiol also binds tightly (0.12 +/- 0.02 nM), 2-hydroxyestradiol and 4-hydroxyestrone with intermediate affinity (0.26 +/- 0.06 and 0.28 +/- 0.07 nM, respectively), and 2-hydroxyestrone and 2-hydroxyestriol much less well (1.68 +/- 0.79 and 1.27 +/- 0.26 nM, respectively). The binding of the 2-methoxyestrogens is extremely weak. These receptor affinities roughly parallel the potencies of these compounds in altering gonadotropin secretion. Topics: 2-Methoxyestradiol; Animals; Binding Sites; Catechol O-Methyltransferase; Cytosol; Estradiol; Estriol; Female; Hydroxyestrones; Hypothalamus; Liver; Methylation; Pituitary Gland; Rats; Receptors, Estrogen; Substrate Specificity; Uterus | 1980 |
Convenient large scale preparation of catechol estrogens.
2-Hydroxyestrone, 2-hydroxyestradiol-17beta, 2-hydroxy-17alpha-ethynylestradiol, 2-hydroxyestriol, 4-hydroxyestrone, 4-hydroxyestradiol-17beta, 4-hydroxy-17alpha-ethynylestradiol and 4-hydroxyestriol are prepared on a preparative scale from the corresponding aminophenols using a new inverse oxidation procedure. By the synthesis described both the 2- and 4-hydroxylated estrogens are available in high yields. Topics: Catechols; Chemical Phenomena; Chemistry; Estradiol; Estriol; Estrogens; Estrogens, Catechol; Ethinyl Estradiol; Hydroxyestrones; Methods | 1976 |