The Relationship between Gastric Juice Nitrate/Nitrite Concentrations and Gastric Mucosal Surface pH

ABSTRACT

PURPOSE: To investigate gastric juice nitrate/nitrite concentration according to mucosal surface pH extent (area) of gastric corpus intimately contacting the gastric juice. MATERIALS AND METHODS: We included ninety-nine patients with dyspepsia. To evaluate gastric mucosal surface pH and its extent, gastric chromosocpy was performed by spraying phenol red dye on the corpus mucosa and estimating the extent of area with color changed. Nitrate/nitrite concentrations and pH of gastric juice were measured by ELISA and pH meter, respectively. Silver staining was done to histologically confirm the presence of Helicobacter pylori. RESULTS: Intragastric nitrate/nitrite concentrations in patients, showing phenol red staining mucosa were higher than those of unstaining mucosa (p=0.001): the more extensive in the area of phenol red staining area of corpus, the higher gastric juice pH found (r=0.692, p<0.001). Furthermore, the intragastric nitrate/nitrite concentrations correlated positively with gastric juice pH (r=0.481, p<0.001). CONCLUSION: The changes of mucosal surface pH and its extent in gastric corpus might affect either pH or nitrate/nitrite level of gastric juice.