Evidence of NPY Y5 receptor involvement in food intake elicited by orexin A in sated rats.
Intracerebroventricular (icv) injections of orexin A stimulate feeding in sated rats. Since neuropeptide Y is a potent orexigenic peptide and orexin-containing neurons are morphologically linked with NPY-producing neurons in the hypothalamus, we evaluated the functional relationship between the two orexigenic peptides. The results show that whereas it was ineffective on its own, a selective NPY Y5 receptor antagonist, injected icv 15 min. before orexin A significantly suppressed orexin A-induced feeding. Since previous investigations demonstrated that an NPY Y1 receptor antagonist also inhibits feeding induced by orexin A, the current results further underscore the existence of a functional link between orexin and NPY producing neurons as the orexin network appears to be capable of influencing NPYergic signaling through Y1 and Y5 receptors to stimulate feeding.
Dube
M G
MG
Department of Physiology, P.O. Box 100274, University of Florida College of Medicine, Gainesville, FL 32610-0274, USA. mdube@ufl.edu
Horvath
T L
TL
Kalra
P S
PS
Kalra
S P
SP
D000818:Animals; D001067:Appetite Depressants / Q000494:pharmacology; D001069:Appetite Regulation / Q000187:drug effects*; D002352:Carrier Proteins / Q000008:administration & dosage / Q000494:pharmacology*; D004435:Eating / Q000187:drug effects; D005247:Feeding Behavior / Q000187:drug effects; D007276:Injections, Intraventricular; D047908:Intracellular Signaling Peptides and Proteins; D008297:Male; D009281:Naphthalenes / Q000494:pharmacology; D009419:Nerve Tissue Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D009474:Neurons / Q000187:drug effects / Q000378:metabolism; D009479:Neuropeptides / Q000008:administration & dosage / Q000494:pharmacology*; D064446:Orexin Receptors; D000068797:Orexins; D011743:Pyrimidines / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D043562:Receptors, G-Protein-Coupled; D018013:Receptors, Neuropeptide; D017476:Receptors, Neuropeptide Y / Q000037:antagonists & inhibitors / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects; D015430:Weight Gain / Q000187:drug effects
D001067:Appetite Depressants; D002352:Carrier Proteins; D047908:Intracellular Signaling Peptides and Proteins; D009281:Naphthalenes; D009419:Nerve Tissue Proteins; D009479:Neuropeptides; D064446:Orexin Receptors; D000068797:Orexins; D011743:Pyrimidines; D043562:Receptors, G-Protein-Coupled; D018013:Receptors, Neuropeptide; D017476:Receptors, Neuropeptide Y; C100568:neuropeptide Y5 receptor; C116786:CGP 71683 A