Liver aquaporins: significance in canalicular and ductal bile formation.

Abstract Bile is primarily secreted in hepatocytes (i.e. the canalicular bile) and subsequently delivered to the intrahepatic bile ducts, where is modified by cholangiocytes (i.e. the ductal bile). Bile formation is the result of the coordinated interactions of membrane-transport systems that generate the vectorial movement of solutes and osmotically driven water molecules. Hepatocytes and cholangiocytes express aquaporins, specialized membrane channel proteins that facilitate the osmotic transport of water. In this review, we provide a summary of what is known on liver AQPs and their significance in canalicular and ductal bile formation under normal and pathological conditions.