The pH of the Gastric Mucosal Surface and Helicobacter pylori Infection in Non-Ulcer Dyspepsia

Chae, Hiun Suk; Chung, In Sik; Sun, Hee Sik; Park, Doo Ho; Han, Sok Won; Choi, Kyu Yong; Jang, Sung Won; Yoon, Jong Goo; Kim, Young Shin; Lee, An Hi

Abstract

BACKGROUND/AIMS: The Helicobacter pylori(H. pylori) infection induces gastric mucosal injury through the various bacterial cytotoxins, the inflammatory reaction of the host and the increased gastric acid secretion. Urease is a kind of adaptive protein of H. pylori to survive in strong acid environment of the stomach, may increase the pH of the gastric mucosal surface and induces gastrin release by the feedback mechanism. This study was performed to evaluate whether 0.1% phenol red solution without urea is useful as a pH indicator of the gastric mucosa for the diagnosis of H. pylori infection in stomach and whether the pH of the gastric mucosal surface is changed by H. pylori infection.
METHODS
The gastric mucosa was stained by 0.1% phenol red solution without urea during endoscopy in 89 patients with non-ulcer dyspepsia. The patterns of staining of the gastric mucosa were divided into unstained, patchy regional and diffuse staining by the area of color change from yellow to red. The pH of the gastric mucosal surface was measured directly on the stained and unstained areas of the gastric mucosa by using pH meter and antimony pH electrode through the biopsy channel.
RESULTS
The pH of the stained areas after spray of phenol red solution was significantly higher(6.9) than that(1.9) of the unstained gastric mucosa(P<0.01). The patterns of the staining were different between antrum and body. The patterns of unstaining and patchy staining were more common in the body than in the antrum. But the patterns of regional and diffuse staining were more common in the antrum than in the body(P<0.05). The positive rates of H. pylori in antrum, body and total gastric biopsies were higher in stained than in unstained mucosa significantly(P<0.05). Severity of active inflammatory reactions was higher in stained mucosa than unstained mucosa in the antrum. But there was no difference in severity of active inflammatory reactions between stained mucosa and unstained mucosa in the body.
CONCLUSIONS
0.1% phenol red solution without urea is useful as a pH indicator for the diagnosis of the H. phlori infection in the stomach. H. pylori infection may increase the pH of gastric mucosal surface and induce severe active inflammation of the gastric mucosa in non-ulcer dyspepsia.