Effects of nociceptin (13-17) in pain modulation at supraspinal level in mice.
This work was designed to observe the effects of nociceptin(13-17), one of the main metabolites of nociceptin (also termed orphanin FQ), in pain modulation at supraspinal level in mice. Intracerebroventricular (i.c.v.) administration of nociceptin/orphanin FQ(13-17) (N/OFQ(13-17)) (5, 0.5, 0.05, 0.005 nmol/mouse) dose-dependently induced potent hyperalgesic effects in the 48 degrees C warm-water tail-flick test in mice. I.c.v. pretreatment with N/OFQ(13-17) (5, 0.5, 0.05 nmol/mouse) potentiated the analgesic effects induced by morphine (i.p., 2 mg/kg) and reversed the hyperalgesic effects induced by N/OFQ (i.c.v., 5 nmol/mouse). The hyperalgesic effects induced by N/OFQ(13-17) could not be antagonized by [Nphe((1))]N/OFQ(1-13)NH((2)) or naloxone. These findings suggest that N/OFQ(13-17) may play important roles in pain modulation at supraspinal level in mice and elicits these effects through a novel mechanism independent of the N/OFQ receptor and the mu, delta and kappa opioid receptors.
D000698:Analgesia; D000701:Analgesics, Opioid / Q000008:administration & dosage / Q000494:pharmacology; D000818:Animals; D004305:Dose-Response Relationship, Drug; D006358:Hot Temperature; D006930:Hyperalgesia / Q000139:chemically induced* / Q000503:physiopathology; D007276:Injections, Intraventricular; D008297:Male; D051379:Mice; D009020:Morphine / Q000008:administration & dosage / Q000494:pharmacology; D009270:Naloxone / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology; D018847:Opioid Peptides / Q000008:administration & dosage / Q000494:pharmacology*; D010147:Pain Measurement; D010446:Peptide Fragments / Q000008:administration & dosage / Q000494:pharmacology*; D014665:Vasodilator Agents / Q000008:administration & dosage / Q000494:pharmacology*; D000097629:Nociceptin
D000701:Analgesics, Opioid; D009020:Morphine; D009270:Naloxone; D018847:Opioid Peptides; D010446:Peptide Fragments; D014665:Vasodilator Agents; D000097629:Nociceptin; C439964:nociceptin (1-13) amide; C024224:naloxazone