title: Effect of topical administration of L-arginine on formalin-induced nociception in the mouse: a dual role of peripherally formed NO in pain modulation.
abstract: 1. We investigated the effects of intraplantar (i.pl.) administration of L-arginine and NG-nitro-L-arginine methyl ester (L-NAME) on formalin-induced behavioural nociception in the mouse. 2. L- but not D-arginine, at 0.1-1 microgram per paw, coadministered with i.pl. formalin, enhanced the second-but not the first-phase nociceptive responses, whereas it was without significant effects at 3 micrograms per paw, and conversely, produced antinociception at 10 micrograms per paw, resulting in a bell-shaped dose-response curve. 3. L-NAME at 0.1-1 microgram per paw, when administered i.pl., exhibited antinociceptive activity in the second phase in a dose-dependent manner, although its D-enantiomer produced no effect. 4. An antinociceptive dose (1 microgram per paw) of L-NAME (i.pl.) considerably reduced the increase in second-phase nociception elicited by low doses (1 microgram per paw) of i.pl. L-arginine. The second-phase nociception decrease induced by a large dose (10 micrograms per paw) of i.pl. L-arginine was markedly reversed by i.pl. L-NAME at 0.1 micrograms per paw, raising it to a level above that of the control (formalin only). 5. These results suggest that peripheral NO plays a dual role in nociceptive modulation, depending on the tissue level, inducing either nociceptive or antinociceptive responses.
authors.affiliation: Department of Pharmacology, Faculty of Pharmaceutical Sciences, Kinki University, Higashi-Osaka, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Kawabata
authors.forename: S
authors.initials: S
authors.lastname: Manabe
authors.forename: Y
authors.initials: Y
authors.lastname: Manabe
authors.forename: H
authors.initials: H
authors.lastname: Takagi
mesh_terms: D000287:Administration, Topical; D000594:Amino Acid Oxidoreductases / Q000037:antagonists & inhibitors; D000818:Animals; D001120:Arginine / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000494:pharmacology*; D001522:Behavior, Animal / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D005557:Formaldehyde; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D019331:NG-Nitroarginine Methyl Ester; D009569:Nitric Oxide / Q000096:biosynthesis / Q000502:physiology*; D019001:Nitric Oxide Synthase; D010146:Pain / Q000378:metabolism / Q000503:physiopathology*; D010147:Pain Measurement / Q000187:drug effects*; D013237:Stereoisomerism
chemical_list: D005557:Formaldehyde; D009569:Nitric Oxide; D001120:Arginine; D019001:Nitric Oxide Synthase; D000594:Amino Acid Oxidoreductases; D019331:NG-Nitroarginine Methyl Ester