title: An electronic pressure-meter nociception paw test for mice.
abstract: The aim of the present investigation was to describe and validate an electronic mechanical test for quantification of the intensity of inflammatory nociception in mice. The electronic pressure-meter test consists of inducing the animal hindpaw flexion reflex by poking the plantar region with a polypropylene pipette tip adapted to a hand-held force transducer. This method was compared to the classical von Frey filaments test in which pressure intensity is automatically recorded after the nociceptive hindpaw flexion reflex. The electronic pressure-meter and the von Frey filaments were used to detect time versus treatment interactions of carrageenin-induced hypernociception. In two separate experiments, the electronic pressure-meter was more sensitive than the von Frey filaments for the detection of the increase in nociception (hypernociception) induced by small doses of carrageenin (30 microg). The electronic pressure-meter detected the antinociceptive effect of non-steroidal drugs in a dose-dependent manner. Indomethacin administered intraperitoneally (1.8-15 mg/kg) or intraplantarly (30-300 microg/paw) prevented the hypersensitive effect of carrageenin (100 microg/paw). The electronic pressure-meter also detected the hypernociceptive effect of prostaglandin E2 (PGE2; 10-100 ng) in a dose-dependent manner. The hypernociceptive effect of PGE2 (100 ng) was blocked by dipyrone (160 and 320 microg/paw) but not by intraplantar administration of indomethacin (300 microg/paw). The present results validate the use of the electronic pressure-meter as more sensitive than the von Frey filaments in mice. Furthermore, it is an objective and quantitative nociceptive test for the evaluation of the peripheral antinociceptive effect of anti-inflammatory analgesic drugs, which inhibit prostaglandin synthesis (indomethacin) or directly block the ongoing hypernociception (dipyrone).
authors.affiliation: Departamento de Farmacologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brasil.
authors.forename: T M
authors.initials: TM
authors.lastname: Cunha
authors.forename: W A
authors.initials: WA
authors.lastname: Verri
authors.forename: G G
authors.initials: GG
authors.lastname: Vivancos
authors.forename: I F
authors.initials: IF
authors.lastname: Moreira
authors.forename: S
authors.initials: S
authors.lastname: Reis
authors.forename: C A
authors.initials: CA
authors.lastname: Parada
authors.forename: F Q
authors.initials: FQ
authors.lastname: Cunha
authors.forename: S H
authors.initials: SH
authors.lastname: Ferreira
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology*; D002351:Carrageenan / Q000494:pharmacology; D015232:Dinoprostone / Q000494:pharmacology; D004177:Dipyrone / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D007213:Indomethacin / Q000494:pharmacology; D051379:Mice; D010147:Pain Measurement / Q000295:instrumentation / Q000379:methods*; D011312:Pressure; D011930:Reaction Time; D012680:Sensitivity and Specificity
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D004177:Dipyrone; D002351:Carrageenan; D015232:Dinoprostone; D007213:Indomethacin