GASTRIC AND DUODENAL JUXTAMUCOSAL PH AND HELICOBACTER-PYLORI

One of the results of gastric cytoprotection is the generation of a ju xtamucosal stable pH, maintained close to neutrality by several factor s among which bicarbonate secretion and mucus layer. Since Helicobacte r pylori (HP) induces structural and functional changes in the gastric mucus, this study was carried out to investigate the relationship bet ween juxtamucosal pH and HP colonization. Thirty-one dyspeptic subject s who denied a past history of gastric or duodenal ulcer and free of e ndoscopic lesions were studied. Juxtamucosal pH of the gastric body, a ntrum and duodenum and gastric luminal fluid pH were measured during u pper gastrointestinal endoscopy by a flexible glass electrode passed t hrough the biopsy channel of a gastroscope. Multiple biopsies were sub sequently taken for histological investigation, HP culture and a urea quick test. Twelve subjects (39%) were infected by HP (HP+). Juxtamuco sal pH (mean +/- SE) was significantly lower (p = 0.0014) in the gastr ic body (5.67 +/- 0.16) in HP+ than in HP-negative (HP- 6.41 +/- 0.13 subjects, but not in the antrum (6.50 +/- 0.20 in HP+ vs. 6.52 +/- 0.0 9 in HP-) and in the duodenum (6.80 +/- 0.14 in HP+ vs. 6.94 +/- 0.08 in HP-subjects). No difference was found in gastric luminal fluid pH ( 1.71 +/- 0.23 in HP+ vs. 1.80 +/- 0.22 in HP-subjects). In conclusion, this study shows that dyspeptic HP+ patients have a reduced juxtamuco sal pH in the gastric body but a pH in the antrum and duodenum similar to HP-subjects.