Duodenal acid-induced inhibition of gastric motility and emptying in rats

Helen E Raybould, H. H. Holzer

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33 Scopus citations

Abstract

The mechanism by which acid in the duodenum inhibits proximal gastric motor function and delays emptying was investigated in urethan-anesthetized and awake rats. Gastric motility inhibited by duodenal acid (0.2 N HCl) in urethananesthetized rats was attenuated by 68 and 54%, respectively, by functional ablation of the vagal or spinal sensory innervation with capsaicin. 5-Hydroxytryptamine3 receptor blockade with zacopride (0.2 mg/kg ip) or cholecystokinin (CCK)-A-type receptor blockade with MK-329 (1 mg/kg ip) had no effect on the motility response to acid. In awake rats with chronically implanted gastric and duodenal cannulas, perfusion of the duodenum with acid (0.1 and 0.2 N HCl) inhibited gastric emptying of a nonnutrient liquid (38 and 59%, respectively). Blockade of CCK-A-type receptors reduced by 30% inhibition of gastric emptying induced by 0.1 N HCl. However, functional ablation of the vagal or spinal sensory innervation, 5- hydroxytryptamine3 receptor blockade, or immunoneutralization of secretin by systemic administration of a polyclonal antibody (no. 7842, 1 ml ip) had no effect on acid-induced (0.1 N HCl) inhibition of gastric emptying. Perfusion of the duodenum with 0.2 N HCl but not 0.1 N HCl inhibited proximal gastric motility in awake rats. These results suggest that 1) a duodenal acid load inhibits gastric emptying in part by a mechanism involving CCK and 2) decreased proximal gastric motility plays a minor role in inhibition of gastric emptying in response to acid.

Original languageEnglish (US)
JournalAmerican Journal of Physiology - Gastrointestinal and Liver Physiology
Volume265
Issue number3 28-3
StatePublished - 1993
Externally publishedYes

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Keywords

  • 5-hydroxytryptamine receptors
  • acid
  • capsaicin
  • cholecystokinin
  • duodenum
  • gastric emptying
  • secretin
  • sensory
  • urethan anesthesia

ASJC Scopus subject areas

  • Physiology
  • Gastroenterology

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