Effect of sodium taurocholate on hepatic uptake and biliary excretion of organic anions in rats.

Hepatic uptake and biliary excretion of some exogenous organic anions administered simultaneously with sodium taurocholate (TC) have been investigated in anaesthetized (1.2 g/kg urethane i.p.) rats. TC (100 or 200 mumol/kg i.v.) significantly increased the biliary excretion of indocyanine green (ICG), bromcresol green (BCG), rose bengal (RB) and bromsulphthalein (BSP). The biliary excretion rates of eosine (EO) and bromsulphthalein-glutathione conjugate (BSP-GSH) were not affected by TC. However, simultaneously given TC significantly reduced the biliary excretion of amaranth (AM). The effect of TC on the biliary excretion rates of organic anions seems to depend on the properties of the anions investigated. ICG, BCG, RB and BSP depress bile production, inhibit mitochondrial respiration and are excreted at low rates. Biliary excretion of these anions was enhanced by TC. EO, BSP-GSH and AM had no depressing effect on the function of liver cells and showed higher excretory rates than the above-mentioned substances. The changes in biliary flow measured during excretion of drugs did not parallel the changes in biliary excretion rate. The hepatic uptake of all organic anions studied was depressed by TC. This finding indicates that no correlation exists between the effects of TC on hepatic uptake and biliary excretion of organic anions.