Intracerebroventricular neuropeptide Y increases gastric and pancreatic secretion in the dog

BACKGROUND: Neuropeptide Y (NPY), a centrally located neurotransmitter, is known to increase appetite in fasted and satiated animals. In addition to evaluating NPY's effect on eating behavior, this study was intended to determine whether intracerebroventricular (ICV) NPY would have an effect on canine gastric and pancreatic secretion. METHODS: Four dogs were prepared with cerebroventricular guides and gastric and pancreatic fistulas. ICV and intravenous NPY was administered during intragastric titration of a glucose and peptone meal. During this study, gastric and pancreatic secretion was measured, as well as insulin levels and pancreatic polypeptide (PP). An additional set of four dogs were prepared with esophageal fistulas and cerebroventricular guides, and the effect of ICV NPY on sham feeding was studied. RESULTS: ICV NPY significantly increased sham feeding, meal-stimulated gastric and pancreatic secretion, basal gastric acid, pancreatic bicarbonate, insulin levels, and PP. Vagotomy blocked the effect of ICV NPY on gastric acid secretion in a urethane-anesthetized rat model with acute gastric fistula. CONCLUSIONS: ICV NPY increased sham feeding, gastric and pancreatic secretion, insulin levels, and PP in the dogs. NPY's effect on gastric secretion was blocked by vagotomy in a rat model. NPY should be considered a candidate mediator of cephalic phase secretion.