title: Comparison of endothelium-derived relaxing factor activity between nonpregnant and pregnant rats.
abstract: The tension of isolated ring preparation of aorta from nonpregnant and pregnant rats was measured isometrically to study the effect of pregnancy on endothelium-derived relaxing factor activity. Contraction in response to norepinephrine and potassium chloride was greater in aortae from nonpregnant rats than in those from pregnant rats. The endothelium-dependent relaxation that was caused by acetylcholine (10(-10)-3 x 10(-9) M) in aortae precontracted with norepinephrine was significantly enhanced in aortae from pregnant rats compared with the relaxation in those from nonpregnant rats. NG-nitro-L-arginine methyl ester (L-NAME) inhibited the endothelium-dependent relaxation in both aorta from pregnant and nonpregnant rats. L-Arginine reversed the inhibition of L-NAME. Those results suggest that the enhanced endothelium-derived relaxing factor activity in rats aortae is associated with pregnancy.
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: Kaneko
authors.forename: M
authors.initials: M
authors.lastname: Kondo
authors.forename: H
authors.initials: H
authors.lastname: Kogo
mesh_terms: D000643:Ammonium Chloride / Q000494:pharmacology; D000818:Animals; D001013:Aorta, Thoracic / Q000187:drug effects; D002117:Calcitriol / Q000008:administration & dosage* / Q000627:therapeutic use; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004958:Estradiol / Q000097:blood; D005260:Female; D066298:In Vitro Techniques; D007537:Isometric Contraction / Q000502:physiology; D009131:Muscle, Smooth, Vascular / Q000502:physiology; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000378:metabolism*; D011374:Progesterone / Q000097:blood; 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; D000643:Ammonium Chloride; D009569:Nitric Oxide; D011374:Progesterone; D004958:Estradiol; D019001:Nitric Oxide Synthase; D002117:Calcitriol; D019331:NG-Nitroarginine Methyl Ester