[Intracellular and extracellular activity of cathepsin D in the liver in cirrhosis and its involution].

The distribution of cathepsin D in liver with CCl4 induced cirrhosis and its involution in rats was investigated by ultrastructural cytochemistry. Besides intracellular, it was revealed the extracellular activity of cathepsin D. The reaction product was on collagen fibers near the hepatocytes and connective tissue cells as well as on the hepatocytes microvilli and on the outside part of cellular membrane of connective tissue cells (macrophage, fibroblast, Ito cells). Hence the source of extracellular cathepsin D in liver are the parenchymatous as well as nonparenchymal cell elements. The results testify that under the cirrhosis and its involution, the cathepsin D takes part in intracellular proteolysis and is secreted by hepatocytes and connective tissue cells in the intracellular space; it also takes part in extracellular catabolism of connective tissue.