title: Antinociceptive effects of mu- and kappa-agonists in inflammation are enhanced by a peripheral opioid receptor-specific mechanism.
abstract: Rats received an injection of Freund's complete adjuvant into the right hindpaw and developed localized inflammation. Four to six days after inoculation, the antinociceptive effect of both the mu-agonist, morphine, and the kappa-agonist U-50,488H, administered subcutaneously, was markedly enhanced in the inflamed paws. This effect was dose dependently antagonized by low dose of intraplantar, but not subcutaneous or intravenous, (-)-naloxone. (+)-Naloxone was inactive. These data indicate that the enhanced antinociceptive effects of both agonists in inflammation are mediated by a peripheral, opioid receptor-specific mechanism.
authors.affiliation: Department of Neuropharmacology, Max-Planck-Institut für Psychiatrie, München, F.R.G.
authors.forename: C
authors.initials: C
authors.lastname: Stein
authors.forename: M J
authors.initials: MJ
authors.lastname: Millan
authors.forename: A
authors.initials: A
authors.lastname: Yassouridis
authors.forename: A
authors.initials: A
authors.lastname: Herz
mesh_terms: D019900:3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer; D000700:Analgesics; D000818:Animals; D005620:Freund's Adjuvant; D007249:Inflammation / Q000188:drug therapy / Q000209:etiology / Q000503:physiopathology; D008297:Male; D009020:Morphine / Q000494:pharmacology; D009270:Naloxone / Q000494:pharmacology; D011759:Pyrrolidines / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D011957:Receptors, Opioid / Q000187:drug effects* / Q000502:physiology; D017473:Receptors, Opioid, kappa; D017450:Receptors, Opioid, mu; D013237:Stereoisomerism
chemical_list: D000700:Analgesics; D011759:Pyrrolidines; D011957:Receptors, Opioid; D017473:Receptors, Opioid, kappa; D017450:Receptors, Opioid, mu; D009270:Naloxone; D019900:3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer; D009020:Morphine; D005620:Freund's Adjuvant