Effect of H. pylori infection on H+/K+-ATPase mRNA expression in gastric fundic gland mucosa in patients with chronic active gastritis and H. pylori infection

Abstract

Backgrounds and Aims: It has recently been shown that Helicobacter pylori (Hp) infection impairs acid secretion. This study was designed to determine the effect of Hp infection on H+/K+-ATPase mRNA expression in gastric fundic gland mucosa. Methods: Twenty patients with chronic gastritis and Hp infection were treated with lansoprazole and amoxicillin and/or clarithromycin. Before and one month after treatment, gastroduodenoscopy was performed, several biopsy specimens were obtained from fundic gland mucosa, and serum gastrin levels were measured by radioimmunoassay (RIA). Total RNA was extracted from fundic gland biopsy specimens, and the amount of H÷/K+-ATPase mRNA in the fundic gland mucosa was measured by a competitive RT-PCR method. Results were standardized by ~-actin mRNA level. Hp infection was diagnosed on the basis of results of culture, rapid urease test (RUT), histology, PCR, and [13C]urea breath test as previously reported (Furuta T, et al. J Clin Microbiol 1996; 34: 2421-5). Results: H+/K÷-ATPase mRNA expression was increased and gastric juice pH and serum gastrin levels were significantly decreased in patients with eradication of Hp. On the other hand, no significant changes in any parameters tested before to after treatment were observed in patients without eradication of Hp. Conclusion: These findings suggest that one of the mechanisms by which Hp infection suppresses acid secretion is inhibition of proton pump synthesis in parietal cells.