Effect of secretin on stress-induced gastric bleeding in rats

The effect of secretin on gastric bleeding induced by water (20 degrees C) immersion stress was studied by means of either perfusion of hydrochloric acid (0.13 N) or instillation of hydrochloric acid solution (0.4 N) into the rat stomach. When the stomach was perfused with acid solution, gastric bleeding occurred 20 min after the stress of water immersion and the amount of bleeding increased with time. It was found that integrated amounts of gastric bleeding after stress were more significantly decreased in the secretin-treated group (7.5 clinical units/kg/hr) than the saline control. On the other hand, intraduodenal administration of cimetidine (100 mg/kg) or propantheline (30 mg/kg) did not affect gastric bleeding. It was also revealed that the total amount of glycoprotein in the 4-hr perfusate was decreased 30% by the water immersion, but that secretin treatment prevented the 30% decrease in glycoprotein in the perfusate. In experiments on intragastric instillation of hydrochloric acid solution, it was found that gastric bleeding was seen only when the concentration of hydrochloric acid solution was higher than 0.4 N. However, the bleeding was also significantly prevented by treatment with secretin (2.5 and 7.5 clinical units/kg/hr). In conclusion, secretin prevents stress-induced gastric bleeding at least in part by increasing glycoprotein secretion in the gastric mucosa in the rat.