title: Nitric oxide synthase inhibitor blocks spinal sensitization induced by formalin injection into the rat paw.
abstract: This study evaluated the role of nitric oxide (NO) in spinal cord nociceptive transmission during peripheral inflammation evoked by formalin injection into the rat paw, using N omega-nitro-L-arginine (N-Arg), an NO synthase inhibitor. Male rats were prepared with intrathecal (IT) catheters. To quantify the formalin response, the instances of "flinching behavior" were counted at 5-min intervals for 60 min. IT N-Arg depressed the flinching behavior in a dose-dependent manner when N-Arg was administered 10 min before the formalin injection. This N-Arg effect was reversed with L-arginine but not D-arginine. We conclude that NO plays an important role in nociceptive transmission in the spinal cord during the formalin test.
authors.affiliation: Department of Anesthesiology, School of Medicine, Chiba University, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Yamamoto
authors.forename: N
authors.initials: N
authors.lastname: Shimoyama
authors.forename: T
authors.initials: T
authors.lastname: Mizuguchi
mesh_terms: D000594:Amino Acid Oxidoreductases / Q000037:antagonists & inhibitors*; D000818:Animals; D001120:Arginine / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D005557:Formaldehyde / Q000633:toxicity*; D007249:Inflammation / Q000139:chemically induced / Q000503:physiopathology*; D007278:Injections, Spinal; D008297:Male; D019001:Nitric Oxide Synthase; D019335:Nitroarginine; D010146:Pain / Q000503:physiopathology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013116:Spinal Cord / Q000187:drug effects / Q000502:physiology*
chemical_list: D005557:Formaldehyde; D019335:Nitroarginine; D001120:Arginine; D019001:Nitric Oxide Synthase; D000594:Amino Acid Oxidoreductases