[The electron-histochemical detection of the activity of thiol proteinases in normal and cirrhotically altered liver].

The distribution co-activity of thiol proteinases (cathepsin B and cathepsin H) was investigated in normal and cirrhotic liver by the electron-cytochemical method. The reaction product was localized on lysosomes of Kupffer's cells, hepatocytes, endotheliocytes and fibroblasts. Extracellular activity of thiol proteinases was revealed in normal as well as in cirrhotic liver. The reaction product was situated on collagen fibrils near hepatocytes and connective tissue cells. The results evidence that besides participation in intracellular degradation of different proteins, thiol proteinases are secreted by hepatocytes and connective tissue cells of the liver to the intercellular space and can take part in extracellular collagen resorption.