Pathogenesis of water-immersion stress-induced gastric ulcers in rats with renal failure.

Rats with or without renal failure, produced by uranyl acetate, were subjected to water-immersion stress for 6 h. The severity of stress-induced gastric ulcers in the renal failure group was significantly higher than that in the control group. The intragastric pH did not significantly differ between the two groups. Transmucosal electrical potential difference, gastric mucosal blood flow, and gastric mucosal hexosamine content in the renal failure group were significantly lower than in the control group. These results suggest that decreases in defensive factors, rather than an increase in an aggressive factor, may be more closely involved in the development of acute gastric ulcers in rats with renal failure.