The D2/D3 agonist PD128907 (R-(+)-trans-3,4a,10b-tetrahydro-4-Propyl-2H,5H- [1]benzopyrano[4,3-b]-1,4-oxazin-9-ol) inhibits stimulated pyloric relaxation and spontaneous gastric emptying

Purna Kashyap, Maria Adelaide Micci, Sarina Pasricha, Pankaj Jay Pasricha

Research output: Contribution to journalArticle

8 Scopus citations

Abstract

Background Enteric neuronal dopamine (DA) inhibits acetylcholine release and gastric motility; this has been thought to be mediated via neuronal dopamine-2 receptor (D2R). The aim of this study was to investigate the modulation of gastric motility by the dopamine-3 receptor (D3R). Methods Adult Sprague-Dawley rats were used. Pyloric relaxation in response to electrical field stimulation (EFS) was assessed in an organ bath in the presence of varying concentrations of a selective D3R agonist, PD128907. Gastric emptying was assessed by the phenol red method after rats were treated with varying doses of PD128907 or DA with and without a selective D3R antagonist, l-nafadotride. Results Immunoblotting and immunohistochemistry confirmed the presence of D3R in the myenteric neurons in the rat pylorus. D3R activation reduced EFS-induced relaxation of pyloric strips in a dose-dependent manner and significantly delayed gastric emptying compared with vehicle. The D3R antagonist partially reversed the effect of DA on gastric emptying. Conclusions Our data suggest a novel role for D3R in regulation of gastric motility. D3R activation delays gastric emptying, an effect that may be due to impairment of pyloric relaxation. D3R antagonists therefore hold promise as useful agents for treatment of gastric motility disorders.

Original languageEnglish (US)
Pages (from-to)57-62
Number of pages6
JournalDigestive Diseases and Sciences
Volume54
Issue number1
DOIs
StatePublished - Jan 1 2009

    Fingerprint

Keywords

  • Dopamine 3 receptor
  • Gastric emptying
  • Rat
  • Stomach

ASJC Scopus subject areas

  • Physiology
  • Gastroenterology

Cite this