PT  - JOURNAL ARTICLE
AU  - M. M. Hadjimarkou
AU  - A. Singh
AU  - Y. Kandov
AU  - Y. Israel
AU  - Y.-X. Pan
AU  - G. C. Rossi
AU  - G. W. Pasternak
AU  - R. J. Bodnar
TI  - Opioid Receptor Involvement in Food Deprivation-Induced Feeding: Evaluation of Selective Antagonist and Antisense Oligodeoxynucleotide Probe Effects in Mice and Rats
AID  - 10.1124/jpet.104.071761
DP  - 2004 Dec 01
TA  - Journal of Pharmacology and Experimental Therapeutics
PG  - 1188--1202
VI  - 311
IP  - 3
4099  - http://jpet.aspetjournals.org/content/311/3/1188.short
4100  - http://jpet.aspetjournals.org/content/311/3/1188.full
SO  - J Pharmacol Exp Ther2004 Dec 01; 311
AB  - Central administration of general and selective opioid receptor subtype antagonists in the rat has revealed a substantial role for μ, a moderate role for κ, and a minimal role for δ receptors in the mediation of deprivation-induced feeding. Antisense probes directed against the κ opioid receptor (KOP), nociceptin opioid receptor (NOP), and δ opioid receptor (DOP) genes in rats result in reductions similar to κ and δ antagonists, whereas antisense probes directed against the μ opioid receptor (MOP) gene produced modest reductions relative to μ antagonists, suggesting that isoforms of the MOP gene may mediate deprivation-induced feeding. Since these isoforms were initially identified in mice, the present study compared the effects of general and selective opioid receptor antagonists on deprivation-induced feeding in rats and mice and antisense probes directed against exons of the MOP, DOP, KOP, and NOP genes on deprivation-induced feeding in the mouse. Food-deprived (12 and 24 h) rats and mice displayed similar profiles of reductions in deprivation-induced feeding following general, μ, and κ opioid antagonists. In contrast, mice, but not rats, displayed reductions in deprivation-induced intake following δ antagonism as well as DOP antisense probes, suggesting a species-specific role for the δ receptor. Antisense probes directed against the KOP and NOP genes also reduced deprivation-induced intake in mice in a manner similar to κ antagonism. However, the significant reductions in deprivation-induced feeding following antisense probes directed against either exons 2, 4, 7, 8, or 13 of the MOP gene were modest compared with μ antagonism, suggesting a role for multiple μ-mediated mechanisms. The American Society for Pharmacology and Experimental Therapeutics