The Role of the Vagal Nerve in Peripheral PYY3-36-induced Feeding Reduction in Rats

Endocrinology. 2005 May;146(5):2369-75. doi: 10.1210/en.2004-1266. Epub 2005 Feb 17.

Abstract

Peptide YY (PYY), an anorectic peptide, is secreted postprandially from the distal gastrointestinal tract. PYY(3-36), the major form of circulating PYY, binds to the hypothalamic neuropeptide Y Y2 receptor (Y2-R) with a high-affinity, reducing food intake in rodents and humans. Additional gastrointestinal hormones involved in feeding, including cholecystokinin, glucagon-like peptide 1, and ghrelin, transmit satiety or hunger signals to the brain via the vagal afferent nerve and/or the blood stream. Here we determined the role of the afferent vagus nerve in PYY function. Abdominal vagotomy abolished the anorectic effect of PYY(3-36) in rats. Peripheral administration of PYY(3-36) induced Fos expression in the arcuate nucleus of sham-operated rats but not vagotomized rats. We showed that Y2-R is synthesized in the rat nodose ganglion and transported to the vagal afferent terminals. PYY(3-36) stimulated firing of the gastric vagal afferent nerve when administered iv. Considering that Y2-R is present in the vagal afferent fibers, PYY(3-36) could directly alter the firing rate of the vagal afferent nerve via Y2-R. We also investigated the effect of ascending fibers from the nucleus of the solitary tract on the transmission of PYY(3-36)-mediated satiety signals. In rats, bilateral midbrain transections rostral to the nucleus of the solitary tract also abolished PYY(3-36)-induced reductions in feeding. This study indicates that peripheral PYY(3-36) may transmit satiety signals to the brain in part via the vagal afferent pathway.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Afferent Pathways / chemistry
  • Afferent Pathways / physiology
  • Animals
  • Arcuate Nucleus of Hypothalamus / chemistry*
  • Eating / drug effects*
  • Electrophysiology
  • Fluorescent Antibody Technique
  • Male
  • Nodose Ganglion / chemistry
  • Nodose Ganglion / metabolism
  • Peptide Fragments
  • Peptide YY / pharmacology*
  • Proto-Oncogene Proteins c-fos / analysis
  • Rats
  • Rats, Wistar
  • Receptors, Neuropeptide Y / analysis
  • Receptors, Neuropeptide Y / biosynthesis*
  • Receptors, Neuropeptide Y / metabolism
  • Satiation / physiology
  • Vagotomy
  • Vagus Nerve / physiology*

Substances

  • Peptide Fragments
  • Proto-Oncogene Proteins c-fos
  • Receptors, Neuropeptide Y
  • neuropeptide Y2 receptor
  • Peptide YY
  • peptide YY (3-36)