Related Experiment Video
Updated: Jul 12, 2026

Mixed Primary Cultures of Murine Small Intestine Intended for the Study of Gut Hormone Secretion and Live Cell Imaging of Enteroendocrine Cells
Published on: April 20, 2017
PI3 kinase dependent stimulation of gastric acid secretion by dexamethasone
Philipp A Lang1, Roman Schniepp, Philipp Kirchhoff
1Department of Surgery, School of Medicine, Yale University, New Haven, CT 06520-8026, USA.
Abstract:
Excessive gastric acid secretion plays an important role in the pathogenesis of peptic ulcers. Dexamethasone, a widely used drug, is known to stimulate gastric acid secretion and increase the incidence of peptic ulcers. However little is known about the mechanism of the dexamethasone's effect on parietal cells. The present study was performed to investigate the contribution of the phosphatidylinositol-3-kinase (PI3 kinase) to dexamethasone induced stimulation of gastric acid secretion. In vivo pretreatment with dexamethasone injections (150 microg/100g for 3 days) or in vitro exposure to (10 microM for > 20 minutes) significantly increased acid secretion in isolated gastric glands approximately 2-3 fold. The dexamethasone induced stimulation of gastric acid secretion was concentration dependent and significantly blunted by the H+/K2+ ATPase inhibitor omeprazole (200 microM), the PI3 kinase inhibitor Wortmannin (500 nM), the protein kinase inhibitor staurosporine (2.5 microM) and the Cl(-) channel blocker NPPB (100 microM); but not by the H(2) antagonist cimetidine (100 microM). In conclusion, it was observed that dexamethasone's effect on proton extrusion requires the activity of a PI3 kinase pathway, an apical Cl(-) channel and the H2+/K2+ ATPase.
Related Concept Videos
Acid Suppressive Drugs for Peptic Ulcer Disease: Histamine H2-Receptor Antagonists
Hormones Secreted by the Stomach
Each of these hormones secreted by different enteroendocrine cells plays a unique role in digestion. Here are a few examples:
Pathophysiology of Peptic Ulcer Disease: Injurious Factors
In the antrum region, G cells secrete the gastrin hormone that binds to gastrin-cholecystokinin-B (CCK2) receptors on parietal and enterochromaffin-like (ECL) cells in the fundic glands. Simultaneously, the vagus nerve releases acetylcholine, which binds to M3...
Acid Suppressive Drugs for Peptic Ulcer Disease: Proton Pump Inhibitors
Gastric acid, a potent cocktail of hydrogen and chloride ions, is produced in specialized parietal cells within the...
Intestinal Phase of Digestion
The arrival of the chyme in the small intestine distends the duodenum, which triggers the enterogastric reflex. This distension...
Gastric Phase of Digestion
When food enters the stomach, it stretches the stomach walls and activates stretch receptors. This triggers local reflexes of the enteric nervous system, mediated through the myenteric plexus. These...