Potent and specific blockade by AH 22216 of histamine-H2-receptor-mediated acid secretion in isolated rabbit gastric cells.

AH 22216 is a new histamine-H2-receptor antagonist which possesses a triazole ring. When compared to cimetidine, AH 22216 is about 100 times more potent (Ki = 0.21 x 10(-8) M) in inhibiting histamine-stimulated acid secretion in isolated rabbit gastric cells. These two antihistamines have no effect on carbachol-stimulated acid secretion in the system. The data indicate that AH 22216 interacts directly and specifically on the gastric H2-receptor of the parietal cell and are consistent with the reported pharmacological potencies of AH 22216 and cimetidine on histamine-induced gastric-acid secretion in vivo. AH 22216 could thus be a useful therapeutic agent in patients with peptic ulcers.