Intracerebroventricular infusion of neuropeptide Y increases glucose dependent-insulinotropic peptide secretion in the fasting conscious dog

The rapid increase of incretins glucose - dependent insulinotropic peptide (GIP) and glucagon like peptide-1 (GLP-1), within 5-15 min, after food ingestion, suggests that a neural mechanism might be involved in the regulation of their secretion. The aim of this study is to determine whether intracerebroventricular (i.c.v) administration of neuropeptide Y (NPY), a widely distributed neurotransmmiter, can mediate this neural regulation of GIP secretion after food consumption. Six healthy mongrel dogs were utilized for this study. A prototype epicranial apparatus was placed surgically, allowing easy and exact localization of the third ventricle for infusions or sampling. Simultaneous blood sampling was obtained from cannulation. of a hind limb vein. Plasma insulin, and GIP concentrations were measured after i.c.v infusion of S, 10 and 25 mu g of NPY dissolved in 0.5 ml of artificial cerebrospinal fluid (a CSF). The secretion of GIP and insulin were increased after the injection of NPY in a different pattern. our data indicate that NPY might be involved in a possible neural control mechanism of GIP secretion after food consumption. 2008 Elsevier Inc. All rights reserved.