It has been reported that intraventricular administration of the melanocortin 4 receptor (MC4-R) agonist MT II and antagonist SHU9119 alter food intake. We found that MT II and SHU9119 have extremely potent effects on feeding when injected in the paraventricular nucleus (PVN), a site where MC4- R gene expression is very high. Our finding provides direct evidence that MC4-R signaling is important is mediating food intake 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.
Bibliographical noteFunding Information:
This research was supported by the General Research Funds of the Veterans Administration Medical Center, the National Institute of Diabetes and Digestive and Kidney Diseases Grant DK 50456 and by the National Institute of Drug Abuse Grant DA-03999.
- Food intake
- MT II
- Paraventricular nucleus