Substrate specificity of sinusoidal bile acid and organic anion uptake systems in rat and human liver.

The Na+-dependent bile salt uptake systems Ntcp (rodents) and NTCP (human), and the Na+-independent organic anion transporters oatpl (rat) and OATP (human) mediate sinusoidal uptake of a variety of amphipathic organic compounds into hepatocytes. Their properties indicate that an overall hepatic clearance of albumin-bound compounds is mediated by a limited number of multispecific transporters with partially overlapping substrate specificities.