title: Role of spinal cyclooxygenase (COX)-2 on thermal hyperalgesia evoked by carageenan injection in the rat.
abstract: Prostaglandins, which are known to play an important role in the nociceptive transmission in the spinal cord, are produced by cyclooxygenase (COX). Two forms of COX have been identified, COX-1 (constitutive form) and COX-2 (a form highly inducible in response to inflammatory stimuli). COX-2 mRNA was reported to be expressed in the brain in normal rats in the absence of inflammation. We investigated the role of spinal COX-2 in the maintenance of thermal hyperalgesia induced by paw carageenan injection in the rat using NS-398, a selective COX-2 inhibitor. Intrathecally administered NS-398 attenuated the level of thermal hyperalgesia in a dose-dependent manner. This suggested that spinal COX-2 plays an important role in the maintenance of thermal hyperalgesia induced by paw carageenan injection.
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: Nozaki-Taguchi
mesh_terms: D000818:Animals; D002351:Carrageenan; D051546:Cyclooxygenase 2; D052246:Cyclooxygenase 2 Inhibitors; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D006358:Hot Temperature; D006930:Hyperalgesia / Q000503:physiopathology*; D007278:Injections, Spinal; D007527:Isoenzymes / Q000502:physiology*; D008297:Male; D009578:Nitrobenzenes / Q000494:pharmacology*; D010146:Pain / Q000503:physiopathology*; D011451:Prostaglandin-Endoperoxide Synthases / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012684:Sensory Thresholds / Q000187:drug effects*; D013449:Sulfonamides / Q000494:pharmacology*
chemical_list: D052246:Cyclooxygenase 2 Inhibitors; D016861:Cyclooxygenase Inhibitors; D007527:Isoenzymes; D009578:Nitrobenzenes; D013449:Sulfonamides; C080955:N-(2-cyclohexyloxy-4-nitrophenyl)methanesulfonamide; D002351:Carrageenan; D051546:Cyclooxygenase 2; D011451:Prostaglandin-Endoperoxide Synthases