The role of the vagal nerve in peripheral PYY3-36-induced feeding reduction in rats.
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.
Koda
Shuichi
S
Third Department of Internal Medicine, Miyazaki Medical College, University of Miyazaki, Kiyotake, Miyazaki 889-1692, Japan.
Date
Yukari
Y
Murakami
Noboru
N
Shimbara
Takuya
T
Hanada
Takeshi
T
Toshinai
Koji
K
Niijima
Akira
A
Furuya
Mayumi
M
Inomata
Norio
N
Osuye
Kazuhiro
K
Nakazato
Masamitsu
M
D000344:Afferent Pathways / Q000737:chemistry / Q000502:physiology; D000818:Animals; D001111:Arcuate Nucleus of Hypothalamus / Q000737:chemistry*; D004435:Eating / Q000187:drug effects*; D004594:Electrophysiology; D005455:Fluorescent Antibody Technique; D008297:Male; D009620:Nodose Ganglion / Q000737:chemistry / Q000378:metabolism; D010446:Peptide Fragments; D019894:Peptide YY / Q000494:pharmacology*; D016760:Proto-Oncogene Proteins c-fos / Q000032:analysis; D051381:Rats; D017208:Rats, Wistar; D017476:Receptors, Neuropeptide Y / Q000032:analysis / Q000096:biosynthesis* / Q000378:metabolism; D012527:Satiation / Q000502:physiology; D014628:Vagotomy; D014630:Vagus Nerve / Q000502:physiology*
D010446:Peptide Fragments; D016760:Proto-Oncogene Proteins c-fos; D017476:Receptors, Neuropeptide Y; C095889:neuropeptide Y2 receptor; D019894:Peptide YY; C061785:peptide YY (3-36)