Mechanisms of Transport of Tauroconjugated Bile Acids in the Hepatocyte: Functional Significance

Abstract

New techniques such as these employing isolated perfused liver, isolated hepatocytes, and, more recently, membrane vesicles and hepatocyte couplets have increased our understanding of hepatic transport processes. The isolated perfused liver is the most complicated model used to study liver transport, because all aspects of hepatic architecture participate in the process. Highly purified canalicular and/or basolateral rat liver membrane vesicle preparations are very useful for exploring transport function in various domains of the plasma membrane and for identifying and isolating putative membrane carriers. Isolated hepatocytes are simple to prepare and are useful especially in studying uptake function of the hepatocyte. One limitation of this model is that isolated liver cells in suspension lose their polarity; thus, it is impossible to examine canalicular excretion processes. This problem has been partially solved by the use of hepatocyte couplets [12, 31]. However, this technique is technically demanding and does not lend itself to quantification of water or solute flux.