THE ROLE OF THE CANALICULAR MULTISPECIFIC ORGANIC ANION TRANSPORTER IN THE DISPOSAL OF ENDOBIOTICS AND XENOBIOTICS

Bile is an important excretory route for the elimination of amphiphili c organic anions, and hepatocytes are the primary secretory units of b ile formation. The hepatocytic basolateral and canalicular membranes a re equipped with various carrier proteins. Transport across the canali cular membrane represents a major concentrative step. Various ATP-depe ndent transporters have been identified, such as a multispecific organ ic anion transporter (canalicular multispecific organic ion transporte r, cMOAT), a bile acid transporter and several P-glycoproteins. TR(-) rats, which lack cMOAT activity, have been valuable in defining the su bstrate specificity of cMOAT. A wide range of glucuronide-, glutathion e- and sulfate-conjugates are transported by this system.