The fate of clofibrate in the perfused rat liver.

Rat liver perfusions were carried out with [methyl 14C]-labelled chlorophenoxyisobutyrate (CPIB) in the perfusate. In three hours, livers passed 42% of the CPIB into the bile (40% of which was conjugated), oxidized 0.3% to CO2 and retained 2.2% within the liver tissue. The fate of CPID in perfused livers from rats pretreated with clofibrate for one week was similar. Subfractionation of the liver showed that most of the retained radioactivity was located in the cytosol. The substantial uptake and transport of the drug through the tissue show that its effects on liver metabolism could be due to direct action.