Blockade of the nociceptin/orphanin FQ/NOP receptor system in the rat ventrolateral periaqueductal gray potentiates DAMGO analgesia.
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.
Scoto
Giovanna M
GM
Department of Pharmaceutical Sciences-Pharmacology Section, University of Catania, v.le A. Doria 6, 95125 Catania, Italy. scotog@unict.it
Aricò
Giuseppina
G
Ronsisvalle
Simone
S
Parenti
Carmela
C
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
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