Exogenous prostaglandin protects against acid-induced deep mucosal injury by stimulating alkaline secretion in rat duodenum.

In the anesthetized rat, exogenous acid (0.1-0.3 N HCl) perfused through the duodenum produced a dose-related increase in the severity of duodenal villous injury. Increasing the duration of perfusion of the 0.1 N HCl also increased the severity of the injury. The increase in the severity of the lesion score was due to an increase in the percentage of villi with damage extending to the lower half of the villus. 16,16-Dimethyl prostaglandin E2 (dm PGE2, 5 micrograms/kg) administered subcutaneously significantly increased duodenal mucosal alkaline secretion and significantly reduced the duodenal villous injury produced by 0.1 N HCl. The reduction in the severity of the lesion score was due to a decrease in the percentage of villi with the deeper type of damage. These data indicate: (1) perfusion of the rat duodenum with 0.1 N HCl at 0.1 ml/min for 30 min provides a valid model for assessing deep duodenal villous injury, (2) exogenous prostaglandin enhances the resistance of the duodenal mucosa against acid induced deep villous injury, and (3) the enhanced resistance may be mediated at least in part by stimulation of duodenal alkaline secretion. The results support the hypothesis that stimulated duodenal alkaline secretion may play a role in defense of the duodenal mucosa against acid-induced deep villous injury.