title: Effects of 17 beta-estradiol on endothelium-dependent relaxation induced by acetylcholine in female rat aorta.
abstract: Estrogens have been postulated to play an important role in modulation of vascular responses to endogenous reactive substances. The effects of chronic in vivo treatment with 17 beta-estradiol on relaxant responses to acetylcholine were investigated in the rat aorta isolated from prepubertal female rats. The selectivity of effects of 17 beta-estradiol on acetylcholine-induced relaxation was evaluated using histamine, another endothelium-dependent relaxant in the rat aorta. 17 beta-Estradiol significantly enhanced endothelium-dependent relaxation induced by acetylcholine, but did not alter the vascular responses to acetylcholine in endothelium-denuded aortic rings isolated from prepubertal female rats. In contrast, 17 beta-estradiol did not change endothelium-dependent relaxation induced by histamine in endothelium-intact aortic rings. The results of the present study demonstrate that 17 beta-estradiol selectively enhances acetylcholine-induced endothelium-dependent relaxation in the rat aorta.
authors.affiliation: Department of Pharmacology, Tulane University School of Medicine, New Orleans, LA 70112.
authors.forename: D Y
authors.initials: DY
authors.lastname: Cheng
authors.forename: C J
authors.initials: CJ
authors.lastname: Feng
authors.forename: P J
authors.initials: PJ
authors.lastname: Kadowitz
authors.forename: C A
authors.initials: CA
authors.lastname: Gruetter
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology*; D000818:Animals; D001013:Aorta, Thoracic / Q000187:drug effects / Q000502:physiology*; D018723:Bethanechol; D001626:Bethanechol Compounds / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004730:Endothelium, Vascular / Q000502:physiology*; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D006632:Histamine / Q000494:pharmacology; D066298:In Vitro Techniques; D009126:Muscle Relaxation / Q000187:drug effects*; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000502:physiology*; D009638:Norepinephrine / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D001626:Bethanechol Compounds; D018723:Bethanechol; D004958:Estradiol; D006632:Histamine; D000109:Acetylcholine; D009638:Norepinephrine