Identification of central sites involved in butorphanol-induced feeding in rats.
Butorphanol (BT), a mixed kappa- and mu-opioid receptor agonist, induces vigorous food intake in rats. Peripheral injection of BT seems to increase food intake more effectively than intracerebroventricular administration. To further elucidate the nature of BT's influence on consummatory behavior, we examined which feeding-related brain areas exhibit increased c-Fos immunoreactivity (IR) following subcutaneous injection of 4 mg/kg body weight BT, a dose known to induce a maximal orexigenic response. We also evaluated whether direct administration of BT into the forebrain regions activated by peripheral BT injection affects food intake. Peripheral BT administration induced c-Fos-IR in the hypothalamic paraventricular nucleus (PVN), central nucleus of the amygdala (CeA), and nucleus of the solitary tract (NTS). However, 0.1-30 microg BT infused into the CeA, failed to increase food intake 1, 2, and 4 h after injection. Only the highest dose of BT (30 microg) injected into the PVN increased feeding. These results suggest that the PVN, CeA, and NTS mediate the effects of peripherally-injected BT. The PVN or CeA are probably not the main target sites of immediate BT action.
Kim
E M
EM
School of Psychology, University of Ulster, Northern Ireland, Newtonabbey, UK.
Shi
Q
Q
Olszewski
P K
PK
Grace
M K
MK
O'Hare
E
E
Billington
C J
CJ
Levine
A S
AS
D000679:Amygdala / Q000737:chemistry / Q000187:drug effects* / Q000502:physiology; D000818:Animals; D001066:Appetite / Q000187:drug effects*; D019167:Appetite Stimulants / Q000008:administration & dosage / Q000494:pharmacology*; D015415:Biomarkers; D002077:Butorphanol / Q000008:administration & dosage / Q000494:pharmacology*; D002421:Caudate Nucleus / Q000737:chemistry; D004435:Eating / Q000187:drug effects*; D007267:Injections; D007276:Injections, Intraventricular; D007279:Injections, Subcutaneous; D008297:Male; D009292:Narcotic Antagonists / Q000008:administration & dosage / Q000494:pharmacology*; D009419:Nerve Tissue Proteins / Q000032:analysis; D009714:Nucleus Accumbens / Q000737:chemistry; D010286:Paraventricular Hypothalamic Nucleus / Q000737:chemistry / Q000187:drug effects* / Q000502:physiology; D016760:Proto-Oncogene Proteins c-fos / Q000032:analysis; D011699:Putamen / Q000737:chemistry; D051381:Rats; D017207:Rats, Sprague-Dawley; D017473:Receptors, Opioid, kappa / Q000819:agonists*; D017450:Receptors, Opioid, mu / Q000819:agonists*; D012686:Septal Nuclei / Q000737:chemistry; D017552:Solitary Nucleus / Q000737:chemistry / Q000187:drug effects* / Q000502:physiology
D019167:Appetite Stimulants; D015415:Biomarkers; D009292:Narcotic Antagonists; D009419:Nerve Tissue Proteins; D016760:Proto-Oncogene Proteins c-fos; D017473:Receptors, Opioid, kappa; D017450:Receptors, Opioid, mu; D002077:Butorphanol