title: Carrageenan-induced thermal hyperalgesia in the mouse: role of nerve growth factor and the mitogen-activated protein kinase pathway.
abstract: NGF is an important link between inflammation and hyperalgesia and interacts with many different mediators of inflammation, including the MAPK signaling pathway. In these studies, carrageenan-induced thermal hyperalgesia was evaluated in the mouse and the role of NGF and the MAPK pathway investigated. Carrageenan induced a time-dependent inflammation and thermal hyperalgesia, which was maximal 4 h post administration. Both indomethacin (0.3, 1.0 and 10 mg/kg s.c., 30 min pre-carrageenan) and morphine (0.4, 1.2, 4.0 mg/kg; s.c., 30 min pre-hyperalgesia measurement) significantly inhibited carrageenan-induced thermal hyperalgesia and indomethicin inhibited paw inflammation, demonstrating the model as suitable for the assessment of anti-hyperalgesic and anti-inflammatory agents. Anti-NGF (0.67 mg/kg sc, 60 min pre-carrageenan) produced a significant inhibition of thermal hyperalgesia, but not inflammation. NGF itself produced a time-dependent hyperalgesia, but not inflammation, following intraplantar injection. The specific MAPK pathway inhibitor, PD98059 (0.1, 0.3 and 1 mg/kg sc, 30 min pre-carrageenan) significantly inhibited carrageenan-induced hyperalgesia, but not inflammation. These data demonstrate a role for both NGF and the MAPK signaling pathway in the production of thermal hyperalgesia, but not inflammation, in the mouse.
authors.affiliation: Neuroscience Research, SmithKline Beecham Pharmaceuticals, New Frontiers Science Park, Third Avenue, CM19 5AW, Harlow, UK.
authors.forename: M J
authors.initials: MJ
authors.lastname: Sammons
authors.forename: P
authors.initials: P
authors.lastname: Raval
authors.forename: P T
authors.initials: PT
authors.lastname: Davey
authors.forename: D
authors.initials: D
authors.lastname: Rogers
authors.forename: A A
authors.initials: AA
authors.lastname: Parsons
authors.forename: S
authors.initials: S
authors.lastname: Bingham
mesh_terms: D000701:Analgesics, Opioid / Q000494:pharmacology; D000818:Animals; D002351:Carrageenan; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005419:Flavonoids / Q000494:pharmacology; D006614:Hindlimb; D006358:Hot Temperature; D006930:Hyperalgesia / Q000139:chemically induced* / Q000503:physiopathology* / Q000517:prevention & control; D007213:Indomethacin / Q000494:pharmacology; D007249:Inflammation / Q000139:chemically induced; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D009020:Morphine / Q000494:pharmacology; D020932:Nerve Growth Factor / Q000494:pharmacology / Q000502:physiology*; D013997:Time Factors
chemical_list: D000701:Analgesics, Opioid; D016861:Cyclooxygenase Inhibitors; D004791:Enzyme Inhibitors; D005419:Flavonoids; D009020:Morphine; D002351:Carrageenan; D020932:Nerve Growth Factor; D020928:Mitogen-Activated Protein Kinases; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one; D007213:Indomethacin