Buprenorphine increases intake of freely available and operant-contingent food in satiated rats.
Opiate administration increases short-term free feeding in satiated rats. The feeding effects of the mixed opioid receptor agonist/antagonist buprenorphine were examined in both free-feeding and operant chamber paradigms. Buprenorphine (0.1 and 0.3 mg/kg) produced significant increases in short-term free feeding (i.e., 4 h), an effect enhanced by repeated administration. Buprenorphine's effects on operant responding were examined in satiated rats using a fixed ratio (FR) 80 (initial pellet) FR 3 (subsequent pellets) reinforcement schedule. Buprenorphine (0.03-0.3 mg/kg) decreased latency to begin responding for food, and increased total number of pellets consumed in a 1-h session. Increases in food intake relative to control were caused by continued responding for food as sessions progressed. Naloxone suppressed both the free-feeding and operant-contingent intake induced by buprenorphine. Thus, buprenorphine increases both freely available and lever-press contingent food intake.
Rudski
J M
JM
Research and Medicine Service, Veterans Administration Medical Center, Minneapolis, MN 55417, USA.
Thomas
D
D
Billington
C J
CJ
Levine
A S
AS
D000818:Animals; D002047:Buprenorphine / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D003216:Conditioning, Operant / Q000187:drug effects*; D004435:Eating / Q000187:drug effects*; D005502:Food; D008297:Male; D009270:Naloxone / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012055:Reinforcement Schedule; D012054:Reinforcement, Psychology; D012528:Satiety Response / Q000187:drug effects*
D009270:Naloxone; D002047:Buprenorphine