title: [Phe1psi(CH2-NH)Gly2]nociceptin-(1-13)-NH2 acts as an agonist of the orphanin FQ/nociceptin receptor in vivo.
abstract: The orphanin FQ/nociceptin (OFQ/N) derivative peptide, [Phe1psi(CH2-NH)Gly2] nociceptin-(1-13)-NH2 (Phe(psi)), has been claimed to be both an antagonist and an agonist of the orphan opioid receptor (ORL1) in different in vitro assays. We now report the dose-dependent inhibition of morphine analgesia by Phe(psi) in mice, an effect parallel to that of OFQ/N. Further, the anti-opioid actions of OFQ/N are not blocked by Phe(psi). Thus, Phe(psi) acts as an ORL1 receptor agonist, not an antagonist, in vivo.
authors.affiliation: Department of Psychology, Furman University, Greenville, SC 29613, USA. judy.grisel@furman.edu
authors.forename: J E
authors.initials: JE
authors.lastname: Grisel
authors.forename: D E
authors.initials: DE
authors.lastname: Farrier
authors.forename: S G
authors.initials: SG
authors.lastname: Wilson
authors.forename: J S
authors.initials: JS
authors.lastname: Mogil
mesh_terms: D000698:Analgesia; D000818:Animals; D004347:Drug Interactions; D005260:Female; D007274:Injections, Intraperitoneal; D007276:Injections, Intraventricular; D008297:Male; D051379:Mice; D009020:Morphine / Q000037:antagonists & inhibitors*; D009292:Narcotic Antagonists / Q000494:pharmacology*; D018847:Opioid Peptides / Q000494:pharmacology*; D010446:Peptide Fragments / Q000494:pharmacology*; D011957:Receptors, Opioid / Q000819:agonists*; D000094942:Nociceptin Receptor; D000097629:Nociceptin
chemical_list: D009020:Morphine; D009292:Narcotic Antagonists; D018847:Opioid Peptides; D010446:Peptide Fragments; D011957:Receptors, Opioid; D000094942:Nociceptin Receptor; D000097629:Nociceptin; C114149:nociceptin (1-13)-NH2, Phe(1)-psi(CH2-NH)-Gly(2)-; C000722287:Oprl1 protein, mouse