HELICOBACTER-PYLORI-RELATED HYPERGASTRINEMIA IS NOT DUE TO ELEVATED ANTRAL SURFACE PH - STUDIES WITH ANTRAL ALKALINIZATION

It has been postulated that Helicobacter pylori-related hypergastrinaemia is due to bacterial ammonia raising antral surface pH and thus preventing acid inhibition of gastrin release. If true, the infection should not alter gastrin release at neutral intragastric pH. To test this, we have studied basal and meal-stimulated gastrin at uncontrolled pH and at pH > 6 in duodenal ulcer patients before and after eradication of H. pylori. The median integrated gastrin response to the meal alone was 2525 ng/l.min (range, 550-8725) before and 725 ng/l.min (range, 250-2925) after eradication of H. pylori (p < 0.01). The corresponding values when intragastric pH was maintained above 6 were 3700 ng/l.min (range, 1900-14,100) and 1400 ng/l.min (range, 400-3400) (p < 0.01). The median reduction in gastrin after eradication of H. pylori was thus similar when the meal was taken at uncontrolled pH (61%; range, 0-97%) and at pH > 6 (69%; range, 36-89%). Likewise, 5 h of gastric alkalinisation did not cause the basal gastrin values when H. pylori was eradicated to increase to those observed when H. pylori was present. These findings indicate that the hypergastrinaemia is not due to elevated antral surface pH.