title: Acetylcholine-induced relaxation of rat aorta is greatest during estrus in the sexual cycle.
abstract: Acetylcholine (ACh)-induced relaxation in the aortae precontracted with norepinephrine was significantly enhanced in the aortae from estrus (E) rats, compared with that in those from metestrus (D-1), diestrus (D-2) and proestrus (PE) rats. NG-Nitro-L-arginine methyl ester (L-NAME) inhibited the endothelium-dependent relaxation in E rats. These results suggest that there is a difference in ACh-induced relaxation of the thoracic aorta during the sexual cycle of rats, and the relaxation is greatest in E of the sexual cycle; this may be due to a difference in nitric oxide synthesis in the endothelium in the sexual cycle.
authors.affiliation: Department of Pharmacology, Tokyo University of Pharmacy and Life Science, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Honda
authors.forename: H
authors.initials: H
authors.lastname: Ishihara
authors.forename: M
authors.initials: M
authors.lastname: Takei
authors.forename: H
authors.initials: H
authors.lastname: Kogo
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology*; D000818:Animals; D001013:Aorta, Thoracic / Q000187:drug effects*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004971:Estrus / Q000502:physiology*; D005260:Female; D066298:In Vitro Techniques; D009126:Muscle Relaxation / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects*; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D009599:Nitroprusside / Q000494:pharmacology; D009638:Norepinephrine / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D014662:Vasoconstrictor Agents / Q000494:pharmacology; D014665:Vasodilator Agents / Q000494:pharmacology*
chemical_list: D004791:Enzyme Inhibitors; D014662:Vasoconstrictor Agents; D014665:Vasodilator Agents; D009599:Nitroprusside; D019001:Nitric Oxide Synthase; D000109:Acetylcholine; D019331:NG-Nitroarginine Methyl Ester; D009638:Norepinephrine