Helicobacter pylori vaculating cytotoxin inhibits duodenal bicarbonate secretion by a histamine-dependent mechanism

Background & Aims: Helicobacter pylori (HP) infection reduces the secretory capacity of the duodenal mucosa for bicarbonate (Hogan et al. 1996), and CagAVacA positive H.p. extract strongly decreases murine duodenal HCO3- secretion in vitro within one hour (Tuo et al 2004). In this study, we investigated the effect of HP vacuolating cytotoxin (VacA) on duodenal mucosal bicarbonate secretion, and the underlying mechanisms for the VacA-induced reduction in HCO3- secretion. Methods: Bicarbonate secretion by murine duodenal mucosa was examined in vitro in Ussing chambers. H.p. extracts from a VacA producing strain (P…