Related Experiment Video
Updated: Jun 1, 2026

Extrahepatic Bile Duct and Gall Bladder Dissection in Nine-Day-Old Mouse Neonates
Published on: August 23, 2022
Hepatocyte aquaporins in bile formation and cholestasis
Raul Alberto Marinelli1, Guillermo Luis Lehmann, Leandro Raul Soria
1Instituto de Fisiologia Experimental, Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), Facultad de Ciencias Bioquimicas y Farmaceuticas, Universidad Nacional de Rosario, 2000 Rosario, Santa Fe, Argentina. rmarinel@unr.edu.ar
Abstract:
Bile formation by hepatocytes is an osmotic secretory process that is ultimately dependent on the biliary secretion of osmotically-active solutes (mainly bile salts) via specialized canalicular transporters as well as on the water permeability of the canalicular plasma membrane domain. Hepatocytes express aquaporins, a family of membrane channel proteins that facilitate the osmotically-driven movement of water molecules. Aquaporin-8 (AQP8), localized to canalicular membranes, modulates membrane water permeability providing a molecular mechanism for the osmotically-coupled transport of solute and water during bile formation. There is experimental evidence suggesting that defective hepatocyte AQP8 expression leads to alterations in normal bile physiology. Thus, AQP8 protein is downregulated (and canalicular water permeability decreased), in established rat models of cholestasis, such as sepsis-associated cholestasis, estrogen-induced cholestasis and extrahepatic obstructive cholestasis. Moreover, AQP8 gene silencing in the human hepatocyte-derived cell line HepG2 inhibits canalicular water secretion. Based on current knowledge, it is conceivable that cholestasis results from a mutual occurrence of impaired solute transport and AQP8-mediated decrease of canalicular water permeability.
Related Concept Videos
Aquaporins
Hepatic Drug Excretion: Influencing Factors
Hepatic Drug Clearance: Role of Transporters
Bile
Bile is released when dietary fats enter...
Reabsorption and Secretion in the DCT and Collecting Duct
The distal part of the DCT, along with the...
Hepatic Drug Excretion: Enterohepatic Cycling
Post-release drugs and metabolites can be reabsorbed into the body from the intestine. For conjugated metabolites like glucuronides, reabsorption requires enzymatic hydrolysis by intestinal microflora. This...

