title: Gastrointestinal HCO3- transport and epithelial protection in the gut: new techniques, transport pathways and regulatory pathways.
abstract: The concept of a protective alkaline gastric and duodenal mucus layer is a century old, yet it is amazing how much new information on HCO3(-) transport pathways has emerged recently, made possible by the extensive utilization of gene-deleted and transgenic mice and novel techniques to study HCO3(-) transport. This review highlights recent findings regarding the importance of HCO3(-) for mucosal protection of duodenum and other gastrointestinal epithelia against luminal acid and other damaging factors. Recently, methods have been developed to visualize HCO3(-) transport in vivo by assessing the surface pH in the mucus layer, as well as the epithelial pH. New information about HCO3(-) transport pathways, and emerging concepts about the intricate regulatory network that governs duodenal HCO3(-) secretion are described, and new perspectives for drug therapy discussed.
authors.affiliation: Department of Gastroenterology, Hannover Medical School, Hannover, Germany. Electronic address: seidler.ursula@mh-hannover.de.
authors.forename: Ursula E
authors.initials: UE
authors.lastname: Seidler
mesh_terms: D000818:Animals; D001639:Bicarbonates / Q000378:metabolism*; D001692:Biological Transport / Q000502:physiology*; D041981:Gastrointestinal Tract / Q000378:metabolism*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007413:Intestinal Mucosa / Q000378:metabolism* / Q000502:physiology
chemical_list: D001639:Bicarbonates