HEPATOCYTE AQUAPORINS IN BILE PHYSIOLOGY AND DISEASE

MARINELLI, RA; MARRONE, J; SORIA, LR

Physiological Mini Reviews

Argentine Physiological Society

Lugar: La Plata, Argentina; Año: 2015

1669-5410

Bileformation by hepatocytes is an osmotic secretory process resulting from thecanalicular secretion of water in response to osmotic gradients created by theactive transport of solutes, primarily bile salts, and other organic anions.Thus bile secretion would be ultimately dependent on the canalicular expressionof bile salt and organic anion transportersas well as the osmotic water permeability of the canalicular plasmamembrane domain, mainly determined by aquaporin-8 (AQP8) water channels. Compellingexperimental evidence suggests that canalicular AQP8 facilitates theosmotically-coupled transport of solute and water during the formation of bile.Downregulation of AQP8-mediated hepatocyte canalicular water permeability isfound in rat models of hepatocellular cholestasis suggesting that defective hepatocyte AQP8 expression is involved in themolecular mechanisms of bile secretory failure. The study of AQP functionin liver has provided new insights into normal bile physiology and diseasemechanisms, and may yield novel therapies to improve certain cholestatic conditions.