Effect of certain ulcer-healing agents on amphibian gastroduodenal bicarbonate secretion.

The effect of luminal application of aluminum sulphate, sucralfate, and bismuth subcitrate on gastroduodenal alkali secretion has been studied with isolated amphibian mucosa. The mucosa, stripped of its external muscle layer, was mounted in chambers that allowed titration of alkali secretion and measurement of transmucosal potential difference and electrical resistance. Neutral aluminum sulphate (3 X 10(-3) M) increased bicarbonate secretion by fundic (mean +/- SEM = 144 +/- 48%, n = 5, P less than 0.05), antral (mean +/- SEM = 214 +/- 63%, n = 4, P less than 0.05), and duodenal (mean +/- SEM = 133 +/- 44%, n = 6, P less than 0.005) mucosa. Sucralfate (0.5 g/l) stimulated fundic (mean +/- SEM = 183 +/- 87%, n = 4, P less than 0.05) and antral (mean +/- SEM = 156 +/- 58%, n = 5, P less than 0.005) alkali secretion and, at a concentration of 1 g/l, duodenal output (mean +/- SEM = 42 +/- 15%, n = 6, P less than 0.05). Bismuth subcitrate (10(-4) M) produced a significant rise in fundic (mean +/- SEM = 80 +/- 21%, n = 5, P less than 0.05) and duodenal (mean +/- SEM = 62 +/- 7%, n = 6, P less than 0.05) alkali secretion. None of these agents altered transmucosal potential difference or electrical resistance. The actions of these agents on gastroduodenal bicarbonate secretion may be important in their ulcer healing effects.