Helicobacter pylori carbachol stimulated parietal cells on histamine and acid secretion by human

Helicobacter pylon (H pyloon) infection is associated with hypo, normal, and hypersecretory disorders of the gastric mucosa. Pathophysiologicalpathways bywhichHpylori interacts with acid secretion are still unclear. The effects of H pylon on (14C) aminopyrine uptake by human parietal cells were examined as an indirect assay for acid secretion. Isolated oxyntic glands were stimulated with submaximal concentrations of histamine or carbachol and incubated with sonicates of different H pylon strains. Omeprazole and sonicates of Campylobacter jejuni served as positive and negative controls, respectively. Two of four H pylori strains reduced hydrochloric acid sequestration within the parietal cells significantly and in a dose dependent manner in up to 80%. Interaction with acid secretion may therefore constitute a factor contributing to a distinct pathogenicity of Hpylon strains. (Gut 1994; 35: 755-757) Department of Gastroenterology, Heinrich-HeineUniversity, Dusseldorf, Germany H Jablonowski K J Hengels N Kraemer G Strohmeyer Microbiology and Immunology, RuhrUniversity, Bochum, Germany G Geis W Opferkuch Correspondence to: Dr med H Jablonowski, Department of Gastroenterology, HeinrichHeine-University, Moorenstr 5, D40225 Dusseldorf, Germany. Accepted for publication 20 September 1993 Helicobacter pylon (H pylon) causes or is at least associated with different clinical and histological entities such as chronic gastritis, peptic ulcer disease, and even gastric carcinoma. Under these conditions acid secretion varies from hypo to hyperchlorhydria. Recently it has been shown that sonicates of H pylon strongly inhibit acid secretion by rabbit parietal cells.' Rabbits, however, are not natural hosts ofH pylon. In humans H pyloni infection may cause acute epidemic gastritis associated with hypochlorhydria.2-4 Whether hypochlorhydria occurs in every short term H pylon infection is as unknown as the influence of longterm H pylon infection on parietal cell function. We have examined the effects of sonicates ofdifferentHpylon strains on acid secretion from isolated human oxyntic glands, using '4C-aminopyrine ('4C-AP) uptake by the parietal cells. This well established assay indirectly reflects acid production.