Effect of Lanthanum on Acid Secretion from Isolated Mouse Stomach in Vitro

To explore the effect and the mechanism of La3+ on gastric acid secretion (GAS) of isolated mouse stomach with perfused lumen, 12 cm H2O column intragastric pressure-provided, whole stomach preparations from mice were incubated in buffer at 37 ℃ in vitro, and perfusate was measured for pH with a pHS-3 type pH meter. The results show that La3+ (0.41～820×10-6 mol*L-1) significantly promotes GAS in a concentration-dependant manner. Proglutamine, a blocker of gastrin receptor, potently inhibits GAS, and it may block the promotive effect of La3+ on GAS, and this effect increases with the increase of proglutamin concentration. Cimetidine, a blocker of histamine H2 receptor, also potently inhibits GAS, and blocks the promotive effect of La3+ on GAS in the same manner with proglutamine. These results suggest that La3+ promotes GAS in isolated stomach possibly by stimulating the releases of gastrin from G cell and Histamine from ECL cell or by activating the gastrin receptors and Histamine H2 receptors on the parietal cell, thereby accelerating the acid secretion of parietal cells in stomach.