Effect of Helicobacter pylori on parietal cell sensitivity to pentagastrin in duodenal ulcer subjects.

We have investigated the possibility that hypergastrinaemia in chronic Helicobacter pylori infection is a compensatory response to reduced parietal cell sensitivity to gastrin. The acid response to 45-min infusions of pentagastrin at sequential doses (micrograms/kg/h) of 0, 0.031, 0.062, 0.124, and 0.6 was compared before and 1 month after eradication of H. pylori in eight duodenal ulcer patients. The median acid outputs (mmol/h) with the respective infusions were 5.0, 7.5, 26.5, 30.8, and 37.0 when H. pylori-positive and similar at 4.5, 7.1, 22.7, 28, and 31.5 when H. pylori-negative. The median estimated dose of pentagastrin required to produce 50% maximal response (D50) was similar before (0.060 micrograms/kg/h) and after (0.057 micrograms/kg/h) eradication of H. pylori. The median estimated maximal response to pentagastrin (mmol/h) was also similar before (39.2) and after (32.3) treatment. The median basal gastrin concentration was 48 ng/l (range, 22-77) before treatment and fell to 33 ng/l (range, 8-37) after eradication of H. pylori (p = 0.03). These findings show that the parietal cell sensitivity to pentagastrin is unaffected by chronic H. pylori infection in duodenal ulcer subjects and that the hypergastrinaemia cannot be attributed to the bacterium inhibiting parietal cell function.