title: Vascular effects of estrone and diethylstilbestrol in porcine coronary arteries.
abstract: OBJECTIVE
  To explore the effects of different estrogens on vascular function, we compared the vasorelaxant effects of 17beta-estradiol, 17alpha-estradiol, estrone, and the synthetic estrogen diethylstilbestrol (DES) on porcine coronary arterial segments.
  
  
  METHODS
  Porcine coronary arterial rings were contracted with the stable thromboxane A2 analogue U46619 (3 x 10(-8) M), and direct relaxation was examined by the addition of increasing concentrations of 17beta-estradiol, 17alpha-estradiol, estrone, or DES (10(-9) to 10(-4) M). Modulation of agonist-induced contraction and relaxation was studied in coronary arterial rings incubated for 20 minutes with DES or estrone (10(-10)-10(-6) M) with 17beta-estradiol (10(-9) M) as comparison.
  
  
  RESULTS
  Direct relaxation of arterial rings potentiated by these estrogens was recorded with a rank order potency of DES > 17beta-estradiol > estrone > 17alpha-estradiol. 17beta-Estradiol potentiated relaxation responses to sodium nitroprusside and levcromakalim but not bradykinin or A23187 while reducing contractions to 5-hydroxytryptamine and U46619. DES and estrone, both at 10(-6) M, mimicked the 17beta-estradiol-potentiated sodium nitroprusside and levcromakalim relaxation responses. Additionally, the inhibitory effects of 17beta-estradiol (10(-9) M) on 5-hydroxytryptamine- and U46619-induced contractions were partially reproducible by DES (10(-6) M) and estrone (10(-6) M).
  
  
  CONCLUSIONS
  Although DES is the most potent among the tested estrogenic compounds in eliciting relaxation, 17beta-estradiol is more effective than estrone and DES at enhancing endothelium-independent relaxation and reducing vascular contraction in porcine coronary arteries.
authors.affiliation: Department of Pharmacology, University of Hong Kong, Hong Kong, China.
authors.forename: Hwee
authors.initials: H
authors.lastname: Teoh
authors.forename: Adrian
authors.initials: A
authors.lastname: Quan
authors.forename: Susan W S
authors.initials: SW
authors.lastname: Leung
authors.forename: Ricky Y K
authors.initials: RY
authors.lastname: Man
mesh_terms: D019796:15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid / Q000494:pharmacology; D000818:Animals; D003331:Coronary Vessels / Q000187:drug effects*; D019806:Cromakalim / Q000494:pharmacology; D004054:Diethylstilbestrol / Q000494:pharmacology*; D004357:Drug Synergism; D004730:Endothelium, Vascular / Q000187:drug effects / Q000502:physiology; D004958:Estradiol / Q000494:pharmacology; D004970:Estrone / Q000494:pharmacology*; D009119:Muscle Contraction / Q000187:drug effects; D009126:Muscle Relaxation / Q000187:drug effects; D009599:Nitroprusside / Q000494:pharmacology; D013552:Swine; D014662:Vasoconstrictor Agents / Q000494:pharmacology
chemical_list: D014662:Vasoconstrictor Agents; D019806:Cromakalim; D009599:Nitroprusside; D004970:Estrone; D004958:Estradiol; D004054:Diethylstilbestrol; D019796:15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid