Neuropeptide Y blocks and reverses interleukin-1 beta-induced anorexia in rats.
Neuropeptide Y (NPY) increases feeding by direct action in the central nervous system (CNS). Interleukin-1 beta (IL-1 beta), on the other hand, induces anorexia when administered ICV at estimated pathophysiological (e.g., yielded by 1.0 ng/rat dose) and pharmacological (> or = 4.0 ng) concentrations in the cerebrospinal fluid (CSF). In the present study, we investigated NPY/IL-1 beta interactions using the ICV administration. ICV microinfusion of NPY (5.0 micrograms) significantly increased 2-h food intake (by 89%), whereas IL-1 beta decreased 2-h food intake (32% decrease with 1.0 ng/rat; 53% with 4.0 ng/rat; and 51% with 8.0 ng/rat). NPY (5.0 micrograms) blocked the anorexic effect induced by all doses of IL-1 beta when both compounds were administered concomitantly. Central infusion of NPY was also able to induce feeding in IL-1 beta-pretreated rats exhibiting marked anorexia. The results show that ICV-administered NPY blocks and reverses the anorexia induced by estimated pathophysiological and pharmacological concentrations of IL-1 beta in rats. A second interpretation of a data subset is that IL-1 beta attenuates or blocks NPY-induced increase in feeding depending on the IL-1 beta dose used. Blockage and reversal of IL-1 beta-induced anorexia by NPY suggest the importance in studying cytokine-peptide interactions in the regulation of feeding behavior. Understanding these endogenous interactions may produce strategies with potential therapeutic implications for chronic diseases associated with long-term anorexia.
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School of Life and Health Sciences, University of Delaware, Newark 19716, USA.
Ilyin
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Plata-Salamán
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CR
D000818:Animals; D000855:Anorexia / Q000139:chemically induced*; D002552:Cerebral Ventricles; D004333:Drug Administration Routes; D004347:Drug Interactions; D004435:Eating / Q000187:drug effects*; D007375:Interleukin-1 / Q000009:adverse effects / Q000494:pharmacology*; D008297:Male; D009478:Neuropeptide Y / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar
D007375:Interleukin-1; D009478:Neuropeptide Y