title: Pregnancy augments nitric oxide-dependent dilator response to acetylcholine in the human uterine artery.
abstract: The influence of pregnancy on the dilator effects of acetylcholine in the isolated human uterine artery was investigated. Acetylcholine (0.1 nM to 0.1 microM) produced concentration- and endothelium-dependent relaxation of norepinephrine (3 microM)-induced contraction. The relaxation was greater in arteries from pregnant patients (P arteries) than from non-pregnant patients (NP arteries). The maximal relaxation was 53.5+/-3.4% (n=21) in P arteries and 23.5+/-2.5% (n=35) in NP arteries. In both P and NP arteries the cholinergic relaxation was increased in the presence of superoxide dismutase and greatly reduced in the presence of the nitric oxide synthase inhibitors, NG-mono-methyl L-arginine (L-NMMA) and L-nitro-arginine-methylester (L-NAME). The effect of these nitric oxide synthase inhibitors was reversed by L-arginine. We conclude that pregnancy enhances acetylcholine-induced nitric oxide synthesis and release in the human uterine artery.
authors.affiliation: Department of Anesthesiology, The University of Texas Medical Branch, Galveston 77555, USA.
authors.forename: S H
authors.initials: SH
authors.lastname: Nelson
authors.forename: O S
authors.initials: OS
authors.lastname: Steinsland
authors.forename: M S
authors.initials: MS
authors.lastname: Suresh
authors.forename: N M
authors.initials: NM
authors.lastname: Lee
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology*; D000328:Adult; D001158:Arteries / Q000187:drug effects* / Q000502:physiology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009569:Nitric Oxide / Q000502:physiology*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D011247:Pregnancy / Q000502:physiology*; D014599:Uterus / Q000098:blood supply*; D014664:Vasodilation / Q000187:drug effects / Q000502:physiology; D019323:omega-N-Methylarginine / Q000494:pharmacology
chemical_list: D004791:Enzyme Inhibitors; D019323:omega-N-Methylarginine; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; D000109:Acetylcholine; D019331:NG-Nitroarginine Methyl Ester