Gastric secretion and activity-stress lesions in the rat.

In Experiment 1, gastric samples were obtained by means of a pylorus ligation procedure on either the first or last day of the activity-stress procedure. Experimental rats had more stomach lesions and showed a drop in gastric acid on the last day collection. In Experiment 2, rats were surgically prepared with gastric cannulas and pyloric cuffs, and first and last day collections were obtained from the same animal. Experimental activity rats revealed more stomach lesions and a corresponding drop in gastric acid on the last collection than did control rats, which thereby suggests that acid was not a significant etiological variable. The destruction of acid-bearing parietal cells or the back diffusion of hydrogen ions could also explain the low acid values in rats with stomach lesions.