Comparative studies on bile flow and biliary lipid excretion after bile-acid loading in normal and partially hepatectomized rats.

This study was performed to investigate sequential changes in bile secretion and biliary lipids after taurocholic acid (TCA) loading of regenerating rat liver. TCA was administered intravenously at stepwise-increasing doses to groups of non-operated control and partially hepatectomized rats, 24, 72 and 168 h after surgery. Bile flow, bile-acid output (BAO) and phospholipid output (PLO) (expressed per gram of liver) in partially hepatectomized rats increased more than in the controls. Using an isolated perfusion rat-liver system, TCA infusion was also carried out on groups of non-operated control and hepatectomized rats 72 h after operation. Again bile flow, BAO and PLO (expressed per gram of liver) were significantly higher in the partial hepatectomy case, mirroring the results obtained in vivo. When horseradish peroxidase (HRP) was pulse-loaded in isolated perfusion preparations, the second peak of biliary HRP secretion in hepatectomized rats was significantly higher than in controls. We conclude that increased bile-acid flow in partially hepatectomized rats is dependent upon acceleration of vesicular transport accompanying or following proliferation in regenerating livers.