NEUROPEPTIDE-Y FUNCTIONS AS A PHYSIOLOGICAL REGULATOR OF CEPHALIC PHASE ACID-SECRETION

Neuropeptide Y (NPY) has been established as a potent orexigenic pepti de, and recent studies suggest that NPY stimulates cephalic phase secr etion as well. However, it is not known whether NPY's effects are phar macologic or physiologic. In order to determine the physiologic signif icance of NPY, we examined the effects of two putative NPY receptor an tagonists, PYX-1 and PYX-2, on sham Feeding and gastric acid secretion in dogs. Our results demonstrate that intracerebroventricular (i.c.v. ) injection of PYX-1 and PYX-2 at 1000 pmol/kg doses significantly sup presses the gastric acid response to sham feeding in dogs. The volumes sham fed were not significantly altered with i.c.v. administration of the antagonists. Peripheral administration did not affect acid secret ion nor sham feeding volumes. Our data suggest that central administra tion of the novel NPY antagonists, PYX-1 and PYX-2, results in signifi cant suppression of acid secretion in dogs. This supports our hypothes is that NPY functions as a physiologic modulator of cephalic phase aci d secretion.