Pancreatic polypeptide microinjection into the dorsal motor nucleus inhibits pancreatic secretion in rats.

Published

Journal Article

BACKGROUND/AIMS: Pancreatic polypeptide (PP), a hormone released from the pancreas, inhibits pancreatic secretion in vivo but not in vitro, suggesting that the inhibitory action of PP on pancreatic secretion is indirect. Circulating PP in physiological concentrations binds to specific receptors in the dorsal vagal complex in the brainstem. Therefore, the hypothesis of this study was that PP acts centrally and inhibits pancreatic secretion by modulating vagal tone. METHODS: The effects of microinjection of PP into the dorsal motor nucleus on 2-deoxy-D-glucose-stimulated and cholecystokinin octapeptide (CCK-8)-stimulated pancreatic secretion were examined in urethane-anesthetized rats. RESULTS: Microinjection of PP to the dorsal motor nucleus but not brainstem sites outside it inhibited 2-deoxy-D-glucose-stimulated pancreatic flow and protein output. CCK-8-stimulated pancreatic protein output was inhibited by PP in the dorsal motor nucleus in dose-dependent and site-specific manners. The inhibitory effect of PP on CCK-8-stimulated protein output was eliminated by vagotomy. CONCLUSIONS: The results suggest that PP acts in the dorsal motor nucleus to modulate vagal tone on the pancreas, thereby inhibiting pancreatic secretion. This study shows for the first time that the dorsal motor nucleus is involved in central feedback inhibition of the exocrine pancreas.

Full Text

Duke Authors

Cited Authors

  • Okumura, T; Pappas, TN; Taylor, IL

Published Date

  • May 1995

Published In

Volume / Issue

  • 108 / 5

Start / End Page

  • 1517 - 1525

PubMed ID

  • 7729645

Pubmed Central ID

  • 7729645

International Standard Serial Number (ISSN)

  • 0016-5085

Language

  • eng

Conference Location

  • United States