Continuous infusion of neuropeptide Y in the SCN decreases food intake in rats.

We investigated the effect of chronic infusion of neuropeptide Y (NPY) aimed at the hypothalamic suprachiasmatic nucleus (SCN) or the lateral cerebral ventricle (LCV) on food intake. The experiments were performed in adult male Wistar rats infused for 7 days with saline or NPY (10 and 100 pmol microliters-1 h-1) into the SCN (n = 18) or LCV (n = 17). Infusion of the lower dose of NPY in the SCN significantly decreased food intake, whereas infusion of the higher dose did not. There was no change in food intake specific to saline or either dose of NPY with infusion in the LCV. It is concluded that chronic infusion of NPY into the SCN at a dose of 10 pmol h-1 inhibits food intake in rats.