Effects of FPL-52694, a new mast cell stabilizer, on gastric secretion and various acute gastric lesions in rats.

Oral FPL-52694 [5-(2-hydroxypropoxy)-8-propyl-4-oxo-4H-1-benzopyran-2-carboxylic acid Na], a new mast cell stabilizer, dose-dependently inhibited gastric acid secretion but increased the volume and pepsin output in pylorus-ligated rats. Intraduodenal FPL-52694 significantly inhibited all of the volume, acidity, acid output and pepsin output. Concerning the acidity, oral administration of the agent showed much more potent inhibition than intraduodenal administration. Oral FPL-52694 markedly inhibited the development of pylorus-ligated ulcers, water-immersion stress- and aspirin-induced gastric erosions and moderately inhibited the formation of reserpine-induced gastric erosions in rats. Intraduodenal FPL-52694 also inhibited pylorus-ligated ulcers whereas it had no effect on aspirin-induced gastric erosions. Histamine-induced gastric erosions were not affected by oral FPL-52694. These effects of FPL-52694 were almost the same as those of cimetidine, except that cimetidine tended to inhibit histamine-induced gastric erosions. Although the precise mechanism of action of FPL-52694 remains unknown, oral FPL-52694 appears to be a promising agent for the treatment of peptic ulcers.