Abstract
Pantoprazole is an excellent proton pump inhibitor for the treatment of acid-related lesions. In this study we compared the pharmacodynamic effects of (±)-pantoprazole sodium [(±)-PAN·Na] and its enantiomers on gastric acid secretion and their possible side effects on gastric mucus, mucosa, and gastric endocrine cells. (±)-PAN·Na, (-)-PAN·Na, and (+)-PAN·Na dose-dependently inhibited the secretion of basal gastric acid and histamine-induced gastric acid, and (-)-PAN·Na showed the most potent effect, which was confirmed in an in vivo experiment in rabbits and in an in vitro experiment using the stomachs of juvenile rats. On the other hand, (-)-PAN·Na, (+)-PAN·Na, and (±)-PAN·Na did not influence significantly the free and barrier mucus content in rats with short-term administration for 3 days. No obvious differences were observed in serum gastrin levels, volume densities of parietal cells, G cells and D cells, mucosal thickness, or relative stomach weight and body weight among the rats administered (-)-PAN·Na, (+)-PAN·Na, or (±)-PAN·Na for 40 days. Direct administration of (-)-PAN·Na can inhibit gastric acid secretion more effectively with no increase in side effects.
