title: Spinal nociceptin inhibits septide but not N-methyl-D-aspartate-induced nociceptive behavior in rats.
abstract: Nociceptin can induce spinal analgesia in rats. Here, we tested the ability of nociceptin to inhibit the nociceptive behavior (biting, scratching, licking) induced by intrathecal administration of N-methyl-D-aspartate (4 microg) or the tachykinin NK(1) receptor agonist, septide (0.5 microg), in rats. Intrathecal nociceptin (3-30 nmol) did not modify the NMDA-induced behavior. However, coadministration of nociceptin (1-10 nmol) inhibited the septide-induced excitatory response. This inhibition was unaffected by systemic (10 mg/kg) or intrathecal (30 nmol) administration of naloxone, but intrathecal coadministration of the ORL1 (opioid receptor-like type 1) receptor antagonist [Nphe(1)]nociceptin-(1-13)-NH(2) (30-90 nmol) prevented it, suggesting the involvement of ORL1 receptors.
authors.affiliation: Departamento de Medicina, Facultad de Medicina, Laboratorio de Farmacología, Instituto Universitario de Oncología del Principado de Asturias, Universidad de Oviedo, C/ Julián Clavería 6, 33006 Oviedo, Asturias, Spain.
authors.forename: Noemí
authors.initials: N
authors.lastname: Villanueva
authors.forename: Ana
authors.initials: A
authors.lastname: Lastra
authors.forename: Agustín
authors.initials: A
authors.lastname: Hidalgo
authors.forename: Ana
authors.initials: A
authors.lastname: Baamonde
authors.forename: Luis
authors.initials: L
authors.lastname: Menéndez
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects* / Q000502:physiology; D007278:Injections, Spinal; D008297:Male; D016202:N-Methylaspartate / Q000494:pharmacology*; D009270:Naloxone / Q000494:pharmacology; D009292:Narcotic Antagonists; D018847:Opioid Peptides / Q000494:pharmacology*; D010446:Peptide Fragments / Q000494:pharmacology*; D011761:Pyrrolidonecarboxylic Acid / Q000031:analogs & derivatives; D051381:Rats; D017208:Rats, Wistar; D011957:Receptors, Opioid / Q000502:physiology; D013116:Spinal Cord / Q000187:drug effects* / Q000502:physiology; D013373:Substance P / Q000031:analogs & derivatives* / Q000494:pharmacology*; D000094942:Nociceptin Receptor; D000097629:Nociceptin
chemical_list: D016202:N-Methylaspartate; D009270:Naloxone; D009292:Narcotic Antagonists; D018847:Opioid Peptides; D010446:Peptide Fragments; D011761:Pyrrolidonecarboxylic Acid; D011957:Receptors, Opioid; D013373:Substance P; D000094942:Nociceptin Receptor; D000097629:Nociceptin; C054725:septide; C000722285:Oprl1 protein, rat