Absorptive and secretory mechanisms in biliary epithelial cells.
Biliary epithelial cells line the intra- and extrahepatic biliary tree. They are involved in bile formation and are of importance in different cholestatic conditions (vanishing bile duct syndrome). In recent years, progress has been made to elucidate more precisely the physiological role of biliary epithelial cells. Biliary epithelial cells are involved in the cholehepatic shunting of bile acids, they reabsorb sugar and glutamate from bile. Secretin-induced electrolyte secretion is regulated by intracellular cAMP levels in these cells. Intracellular Ca2+ levels, which are increased by different agonists, e.g. carbachol, regulate transmembrane ion channels. ATP acts as secretagogue in these cells by activating ion channels and Na+, H+ antiporter. Further studies have to investigate in which parts of the biliary tree absorptive or secretory mechanisms are predominant.
Elsing
C
C
Department of Medicine, University of Heidelberg, Germany.
Kassner
A
A
Hübner
C
C
Bühli
H
H
Stremmel
W
W
D000042:Absorption; D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D001647:Bile Acids and Salts / Q000378:metabolism; D001659:Biliary Tract / Q000166:cytology / Q000378:metabolism*; D050260:Carbohydrate Metabolism; D018679:Cholinergic Agonists / Q000494:pharmacology; D004847:Epithelial Cells; D004848:Epithelium / Q000378:metabolism; D005110:Extracellular Space / Q000378:metabolism; D018698:Glutamic Acid / Q000378:metabolism; D006801:Humans; D012633:Secretin / Q000378:metabolism; D014867:Water / Q000378:metabolism
D001647:Bile Acids and Salts; D018679:Cholinergic Agonists; D014867:Water; D012633:Secretin; D018698:Glutamic Acid; D000255:Adenosine Triphosphate