title: Nitric oxide mediates rat mucosal vasodilatation induced by intragastric capsaicin.
abstract: The role of endogenous nitric oxide (NO) in the gastric mucosal vasodilatation induced by acute intragastric perfusion with capsaicin or close-arterial infusion of rat alpha-calcitonin gene-related peptide (CGRP) was evaluated in the pentobarbitone-anaesthetised rat using laser Doppler flowmetry (LDF). The mucosal vasodilatation induced by intraluminal capsaicin (160 microM) was dose dependently reduced by the inhibitor of NO synthesis, NG-nitro-L-arginine methyl ester (L-NAME; 1-5 mg kg-1 i.v.), effects reversed by concurrent administration of L-arginine (100 mg kg-1 i.v.). L-NAME (2 mg kg-1) induced a small reduction in the mucosal vasodilatation induced by close-arterial infusion of rat alpha-CGRP (50 pmol kg-1 min-1). These findings indicate a role of NO in the gastric vasodilatation induced by stimulation of sensory neurones with intragastric capsaicin.
authors.affiliation: Department of Pharmacology, Wellcome Research Laboratories, Beckenham, Kent, UK.
authors.forename: B J
authors.initials: BJ
authors.lastname: Whittle
authors.forename: J
authors.initials: J
authors.lastname: Lopez-Belmonte
authors.forename: S
authors.initials: S
authors.lastname: Moncada
mesh_terms: D000594:Amino Acid Oxidoreductases / Q000037:antagonists & inhibitors; D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives / Q000494:pharmacology; D015740:Calcitonin Gene-Related Peptide / Q000494:pharmacology; D002211:Capsaicin / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D005753:Gastric Mucosa / Q000098:blood supply* / Q000187:drug effects; D007834:Lasers; D008297:Male; D019331:NG-Nitroarginine Methyl Ester; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase; D051381:Rats; D014664:Vasodilation / Q000187:drug effects / Q000502:physiology*
chemical_list: D009569:Nitric Oxide; D001120:Arginine; D019001:Nitric Oxide Synthase; D000594:Amino Acid Oxidoreductases; D015740:Calcitonin Gene-Related Peptide; D002211:Capsaicin; D019331:NG-Nitroarginine Methyl Ester