SURFACE pH OF THE GASTRIC MUCOSA IN NORMAL SUBJECTS AND ATROPHIC GASTRITIS

Abstract

The surface pH of the gastric mucosa which were measured at 12 points in each subject by the microglass pH-electrode attached on the gastric fiberscope, were compared with the histologic findings and the gastric secretory functions in 11 cases with normal subjects and 19 cases with atrophic gastritis.
The surface pH of the normal mucosa was mainly above 4.0 in the pyloric gland area, and was less than 4.0 in the fundic gland area. The surface pH of the gastric mucosa was, however, elevated in the fundic gland area in atrophic gastritis corresponding to the degree of the atrophic changes, showing the value of around 7.0 in severe cases. The mucosal pH of each part of the stomach, particulary those of the angle and the body, had significant positive correlation with the atrophic scores, and had significant negative correlations with the gastric secretory functions such as peak acid concentration, maximal acid output and basal acid output.
The patterns of the distribution of the surface pH of the gastric mucosa in atrophic gastritis were classified into the following four types. This classification corresponded well with the histologic findings, and the atrophic border of the gastric mucosa was correctly estimated in almost all cases of atrophic gastritis based on this classification.
Type 1: pH were below 4.0 in antrum, angle and body.
Type 2: pH were below 4.0 in angle and body, and was above 4.0 in antrum.
Type 3: pH was below 4.0 in body, and were above 4.0 in antrum and angle.
Type 4: pH were above 4.0 in antrum, angle and body.
The gastric secretory function was similar in Types 1 and 2, and it diminished in Types 3 and 4, more pronounced in the latter. The cases whose mucosal pH did not fall below pH4.0 at 20 minutes after the stimulation with tetragastrin (4μg/Kg, subcutaneously) showed hypo- or anacidity. It was considered that the measurements of the mucosal pH of the stomach under the direct vision was clinically useful as one of the endoscopical gastric function tests.