[Gastrin/CCK-B receptor antagonists for a novel antiulcer agent].

Gastrin plays an important role in gastrointestinal functions such as gastric secretion and mucosal growth. The hypergastrinemia that results from long-term treatment with proton pump inhibitors and histamine H2-receptor antagonists induces hyperplasia of enterochromaffin-like (ECL) cells and increases the secretory response to pentagastrin (acid rebound). Recently, potent and selective gastrin/CCK-B-receptor antagonists, L-365,260, PD136450 and YM022, have been developed. These compounds inhibit basal and meal-stimulated acid secretion as well as pentagastrin-stimulated acid secretion in rats and dogs. Long-term treatment with gastrin/CCK-B-receptor antagonists does not cause hyperplasia of ECL cells and acid rebound at all. Moreover, they prevent hyperplasia and acid rebound induced by proton pump inhibitors and histamine H2-receptor antagonists. Therefore, gastrin/CCK-B-receptor antagonists are suggested to be novel antiulcer and antisecretory agents without potential for acid rebound, hyperplasia and carcinoid.