Taurolithocholate inhibits taurocholate uptake by isolated hepatocytes at low concentrations

The cholestatic bile acid taurolithocholate inhibits taurocholate uptake by isolated liver cells non-competitively. Inhibition is instantaneous and inversely related to the cell number in the incubate. The Ki amounts to 7 micron in the presence of 2 mg cellular protein per ml. Secretion of taurocholate by isolated liver cells is not affected by taurolithocholate up to a concentration of 50 micron. This indicates a difference between the carrier for taurocholate uptake and the carrier for taurocholate secretion. Inhibition of bile acid uptake of liver cells may be involved in the pathogenesis of lithocholate-induced cholestasis.