Pericentral hepatocytes translocate hydrophilic bile acids more rapidly than hydrophobic ones

The aim of this study was to analyze whether velocity of periportal and pericentral translocation is different for bile acids differing in their physicochemical properties. Isolated livers of male Sprague-Dawley rats were perfused antegradely or retrogradely, in single pass arrangement with labeled taurodehydrocholate, cholate, taurocholate, glycocholate, or taurodeoxycholate (inflow rate: 32 nmol/min/g liver). Bile was collected at 2-min intervals; aliquots were counted in a liquid scintillation spectrophotometer to trace uptake rate and biliary excretion profile. Biliary excretion patterns of all bile acids tested were almost identical in periportal cells; in contrast, it differed greatly in pericentral cells. Pericentral cells excreted taurodehydrocholate as fast as periportal cells, while periportal cells eliminated taurodeoxycholate about four times as fast and cholate, taurocholate and cholate about two times as fast as pericentral cells. It is concluded that, in contrast to periportal translocation, the velocity of pericentral translocation depends upon the hydrophilicity of the respective bile acid. Therefore, different or additional translocation pathways for bile acids may be involved in periportal versus pericentral cells.