FEEDING EFFECTS OF HYPOTHALAMIC INJECTION OF MELANOCORTIN-4 RECEPTOR LIGANDS

It has been reported that intraventricular administration of the melan ocortin 4 receptor (MCL4-R) agonist MT II and antagonist SHU9119 alter food intake. We found that MT II and SHU9119 have extremely potent ef fects on feeding when injected in the paraventricular nucleus (PVN), a site where MC4-R gene expression is very high. Our finding provides d irect evidence that MC4-R signaling is important is mediating food int ake and that melanocortin neurons in the PVN exert a tonic inhibition of feeding behavior. Chronic disruption of this inhibitory signal is a possible explanation of the agouti-obesity syndrome. (C) 1998 Publish ed by Elsevier Science B.V. All rights reserved.