Gastric hypersecretion associated to iodoacetamide-induced mild gastritis in mice.

Disturbances of gastric motor, secretory and/or sensory functions are frequently associated with gastritis. The aim of this study was to characterize motor and secretory alterations associated to chemically-induced gastritis in mice. Mild gastritis was induced with 0.1% iodoacetamide administered intragastrically and added to the drinking water for a 6 days period. A significant loss of body weight and a reduction in food and water intake was observed in iodoacetamide-treated animals compared with those receiving vehicle. At the end of the treatment period, no macroscopic alterations were observed in the gastric mucosa of iodoacetamide-treated mice. However, histological sections revealed a mixed inflammatory infiltrate, with a predominance of mast cells in the submucosa; suggesting a mild gastritis. Gastric emptying rate of a nutrient solid meal was not modified in mice with gastritis compared with normal controls. In animals with gastritis, basal gastric acid secretion was increased compared with normal controls. Basal gastric acid secretion was not modified by either indomethacin or compound 48/80. Secretory response to secretagogues (pentagastrin and histamine) was enhanced during gastritis. Hypersecretory responses to both gastrin and histamine in iodoacetamide-treated mice were blocked by the mast cell stabilizer sodium cromoglycate, and enhanced by indomethacin, without affecting the secretory response in normal mice. These results suggest that mild gastritis alters gastric acid secretory responses through a mechanism related, at least partially, to mast cells activation. Moreover, prostaglandins also modulate secretory responses during mild inflammation. This animal model of gastritis might be useful to characterize pathophysiological changes and potential therapeutic targets in secretory-related gastric pathologies.