title: Blockade of the nociceptin/orphanin FQ/NOP receptor system in the rat ventrolateral periaqueductal gray potentiates DAMGO analgesia.
abstract: Nociceptin/orphanin FQ (N/OFQ) and its receptor (NOP) are involved in various biological functions including pain. High density of NOP receptor has been found in the ventrolateral periaqueductal gray (vlPAG), the main output pathway involved in descending pain-control system. The aim of our work was to evaluate the involvement of the N/OFQ/NOP system in the modulation of MOP analgesia in the rat vlPAG using UFP-101, a selective NOP antagonist. N/OFQ significantly blocked DAMGO (a selective MOP agonist) analgesia, while UFP-101 enhanced the effect of the opioid given at a subanalgesic dose. These results confirm our hypothesis of an antiopioid role for N/OFQ in the vlPAG.
authors.affiliation: Department of Pharmaceutical Sciences-Pharmacology Section, University of Catania, v.le A. Doria 6, 95125 Catania, Italy. scotog@unict.it
authors.forename: Giovanna M
authors.initials: GM
authors.lastname: Scoto
authors.forename: Giuseppina
authors.initials: G
authors.lastname: Aricò
authors.forename: Simone
authors.initials: S
authors.lastname: Ronsisvalle
authors.forename: Carmela
authors.initials: C
authors.lastname: Parenti
mesh_terms: D000701:Analgesics, Opioid / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D020875:Enkephalin, Ala(2)-MePhe(4)-Gly(5)- / Q000008:administration & dosage / Q000494:pharmacology*; D008297:Male; D009292:Narcotic Antagonists; D018847:Opioid Peptides / Q000008:administration & dosage / Q000037:antagonists & inhibitors* / Q000378:metabolism / Q000494:pharmacology; D010147:Pain Measurement; D010487:Periaqueductal Gray / Q000187:drug effects* / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D011957:Receptors, Opioid / Q000378:metabolism; D000094942:Nociceptin Receptor; D000097629:Nociceptin
chemical_list: D000701:Analgesics, Opioid; D020875:Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; D009292:Narcotic Antagonists; D018847:Opioid Peptides; D011957:Receptors, Opioid; D000094942:Nociceptin Receptor; D000097629:Nociceptin; C479838:(Nphe(1),Arg(14),Lys(15))N-OFQ NH(2); C000722285:Oprl1 protein, rat