Mucosal protective effect of leminoprazole on reflux esophagitis induced in rats

We examined the effect of leminoprazole (an acid pump inhibitor) on reflux esophagitis induced in rats. Intragastrically administered leminoprazole significantly and dose-dependently protected the esophageal mucosa against the reflux of gastric contents, without affecting gastric acid secretion. However, it had no effect on the esophagitis when administered intraduodenally, despite its significant inhibition (about 40%) of gastric acid secretion. Omeprazole significantly prevented the development of esophagitis, most probably through potent inhibition of gastric acid secretion. Indomethacin significantly reduced the synthesis of prostaglandin E2 in the esophagus. Since indomethacin pretreatment had no effect on the esophageal protection by leminoprazole, omeprazole or sucralfate, the involvement of endogenous prostaglandins can be ruled out as a possible underlying mechanism. Intragastrically, but not intraduodenally, administered sucralfate significantly prevented the esophagitis even at a dose not affecting gastric acid secretion. These results strongly suggest that both leminoprazole and sucralfate protect the esophageal mucosa directly.