Effect of Certain Ulcer-Healing Agents on Amphibian Gastroduodenal Bicarbonate Secretion

Abstract
The effect of luminal application of aluminium 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 aluminium sulphate (3xl(T'M) increased bicarbonate secretion by fundic (mean ± SEM = 144 ± 48%, n = 5. P < 0.05), antral (mean ± SEM = 214 ± 63%, n = 4, P < 0.05), and duodenal (mean ± SEM = 133 ± 44%, n = 6, P < 0.005) mucosa. Sucralfate (0.5g/1) stimulated fundic (mean ± SEM = 183 ± 87%, n = 4, P < 0.05) and antral (mean ± SEM = 156 ± 58%, n = 5, P < 0.005) alkali secretion and, at a concentration of 1 g/1, duodenal output (mean ± SEM = 42 ± 15%, n = 6, P < 0.05). Bismuth subcitrate (10 4 M) produced a significant rise in fundic (mean ± SEM = 80 ± 21%. n = 5, P < 0.05) and duodenal (mean ± SEM = 62 ± 7%, n = 6, P < 0.005) 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.