Cellular mechanisms of bile formation

Abstract

The mechanisms of bile formation at the level of the hepatocyte have been the subject of intensive research for several decades. These efforts have been hampered, however, by an inability to sample the primary secretion with micropuncture techniques because of the relatively small size (<l pm) of the bile canaliculus. Nevertheless, since the previous review of this field in GASTROENTEROLOGY more than 7 yr ago (l), much has been added to our understanding of the cell biology and physiology of the bile secretory process. Importantly, the results of recent studies have suggested that the basic mechanisms underlying hepatocyte bile secretion may be similar to those responsible for the elaboration of salt and water by many secretory epithelia. In this review, we have limited our discussion to focus on the cellular and tissue aspects of bile water and solute secretion and will not deal with bile ductular or gallbladder modifications or with biliary lipid excretion. Organic anion transport will be considered only as it pertains to the genesis of bile formation.