Regional blood flow and acid secretion associated with damage and restitution of the gastric surface epithelium in cats.

The gastric mucosa of anesthetized cats was exposed to 2 M NaCl for 10 min. After returning to gastric perfusion with 150 mM NaCl and pH 7.40, with and without pentagastrin stimulation, transmucosal potential difference decreased to zero and then gradually increased to approximately half the original value during the following 90 min. H+ secretion decreased and remained close to zero after exposure to 2 M NaCl in nonstimulated cats, whereas pentagastrin-stimulated secretion gradually increased to nearly half the preexposure level. Mucosal blood flow increased, and the vascular resistance decreased in the posterior wall of the stomach corresponding to epithelial damage, as observed by light microscopy after 15 min. Blood flow during pentagastrin stimulation was initially high in fundus and corpus and did not increase further after exposure to 2 M NaCl, but showed similar changes as without pentagastrin in the antrum. Epithelial restitution occurred within 90 min during both nonstimulated conditions and pentagastrin stimulation. In control animals subjected to 150 mM NaCl there were no changes in transmucosal potential difference, H+ secretion, or blood flow throughout the experiment and epithelial damage was not found. In conclusion, damage caused by 2 M NaCl to the gastric surface epithelium was associated with decreased acid secretion and increased mucosal blood flow. These factors may contribute to creating favorable conditions for the epithelial restitution, indicated by restoration of transmucosal potential difference and observed by light microscopy.