title: Antinociceptive effects of metamizol (dipyrone) in rat single motor units.
abstract: Metamizol has been considered as a peripherally acting non-steroidal antiinflammatory drug, though a central action is possible. The aim of the present study was to elucidate if metamizol induces antinociception in the single motor unit preparation, in normal rats versus rats with carrageenan-induced monoarthritis, and whether this action is produced at central and/or peripheral sites. Metamizol induced a potent antinociceptive effect in both groups of animals, though the effect on responses evoked by natural stimulation was stronger in hyperalgesic rats. Metamizol also depressed wind-up in a dose-dependent manner. We conclude that metamizol is a potent antinociceptive agent both in normal and hyperalgesic animals and that the effect was induced both at peripheral and central sites, at the level of the spinal cord.
authors.affiliation: Departamento de Fisiología, Facultad de Medicina, Universidad de Alcalá, Madrid, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Mazario
authors.forename: J F
authors.initials: JF
authors.lastname: Herrero
mesh_terms: D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology*; D001168:Arthritis / Q000139:chemically induced / Q000503:physiopathology; D002351:Carrageenan; D004177:Dipyrone / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004558:Electric Stimulation; D008297:Male; D009046:Motor Neurons / Q000502:physiology*; D009619:Nociceptors / Q000187:drug effects*; D010812:Physical Stimulation; D051381:Rats; D017208:Rats, Wistar; D012018:Reflex / Q000187:drug effects*; D013116:Spinal Cord / Q000166:cytology
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D004177:Dipyrone; D002351:Carrageenan