Chronic intracerebroventricular infusion of nociceptin/orphanin FQ increases food and ethanol intake in alcohol-preferring rats.
Central administration of low doses of nociceptin/orphanin FQ (N/OFQ), the endogenous ligand of the opioid-like orphan receptor NOP, have been shown to reduce ethanol consumption, ethanol-induced conditioned place preference and stress-induced reinstatement of alcohol-seeking behavior in alcohol preferring rats. The present study evaluated the effect of continuous (7 days) lateral brain ventricle infusions of N/OFQ (0, 0.25, 1, 4, and 8 microg/h), by means of osmotic mini-pumps, on 10% ethanol intake in Marchigian-Sardinian alcohol-preferring (msP) rats provided 2h or 24h access to it. N/OFQ dose-dependently increased food intake in msP rats. On the other hand, in contrast to previous studies with acute injections, continuous lateral brain ventricle infusion of high doses of N/OFQ increased ethanol consumption when the ethanol solution was available for 24h/day or 2h/day. The present study demonstrates that continuous activation of the opioidergic N/OFQ receptor does not blunt the reinforcing effects of ethanol. Moreover, the data suggest that continuous activation of the opioidergic N/OFQ receptor is not a suitable way to reduce alcohol abuse.
Cifani
Carlo
C
Department of Experimental Medicine and Public Health, University of Camerino, Via Scalzino 5, 62032 Camerino (MC), Italy.
Guerrini
Remo
R
Massi
Maurizio
M
Polidori
Carlo
C
D000428:Alcohol Drinking; D000437:Alcoholism / Q000503:physiopathology*; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D004435:Eating / Q000187:drug effects*; D000431:Ethanol / Q000008:administration & dosage; D007276:Injections, Intraventricular; D008297:Male; D018847:Opioid Peptides / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D013997:Time Factors; D014665:Vasodilator Agents / Q000494:pharmacology; D000097629:Nociceptin
D000431:Ethanol; D018847:Opioid Peptides; D014665:Vasodilator Agents; D000097629:Nociceptin