Tissue Content and Localization of Lysosomal Enzymes in Cholestatic Rats

Abstract

Levels of the lysosomal enzymes β-glucuronidase and β-hexosaminidase were determined in tissues from rats at 1–7 weeks after permanent bile duct occlusion (28 animals) and sham operation (16 animals). With increasing duration of bile duct occlusion, increasing levels were found in the liver and spleen, whereas levels were unaffected in the pancreas, kidneys, brain, muscle, and skin. Histochemical investigation showed that the lysosomal enzymes accumulated in the hepatocytes and in the increasing numbers of reticuloendothelial cells of the liver and spleen durine cholestasis. No significant accumulation of lysosomal enzymes was seen in the pancreas. In preparations of isolated hepatocytes and non-parenchymal cells increased specific activity of lysosomal enzymes in cholestasis appeared in both cellular fractions. It is assumed that the serum increase of lysosomal enzymes in late cholestasis is partly due to a release from activated macrophages in the liver and spleen.

Key Words:

• Cholestasis
• extrahepatic bile duct obstruction
• hepatocytes
• Kupffer cells
• lysosomal enzymes
• macrophages