Role of Down-Regulated in Adenoma Anion Exchanger in HCO3- Secretion Across Murine Duodenum

In murine duodenum, Dra Cl−/HCO3− exchange is concentrated in the lower crypt-villus axis where it is subject to Cftr regulation. Dra activity contributes most basal HCO3− secretion and ∼50% of cAMP-stimulated HCO3− secretion. Dra Cl−/HCO3− exchange should be considered in efforts to normalize HCO3− secretion in duodenal disorders such as ulcer disease and cystic fibrosis.