Changes of Lysosomes in Autolysis. Histochemical, Biochemical and Electron Microscopic Studies in the Early Stage of Autolysis.

1.Changes of lysosomes of rat hepatic cells in the process of autolysis were investigated histochemically, biochemibally and electron microscopically on the aseptically incubated liver tissues. 2. Lysosomes identified by histochemical examinations of AcPase activity were seen as discrete granules along the bile canalicli of the hepatic cell plates. After 3 hrs. of the incubation, the granules in the hepatic cells surrounding the central vein showed poorly defined contour with decreased density, and the enzymatic activity was not confined to the granules but appeared to disperse into the cytoplasm. With the time of incubation, these changes became distinct and gradually extended to peripheral area of the lobules. 3. Biochemically the AcPase activity in the supernatant fraction and also the activity available in the homogenate showed the gradual increase in the process of incubation. The addition of ATP to the isolated lysosomes protected the membrane against the release of the enzymes concerned. 4. Electron microscopically, among the various morphological changes of the cytoplasmic organelles observed, characteristic changes of the cytoplasmic membranes on the sinusoidal border and those of bile canaliculi and certain alterations of mitochondria were conspicuously noted prior to the ultrastructural alterations of lysosomes. It is concluded that the changes in cytoplasmic membranes of the hepatic cells in the early stages of autolysis precede the release of lysosomal hydrolases, whereas the ATP-level is lowered, the releasing of lysosomal enzymes is accelerated and leads to the lytic changes of the cytoplasm in the later stages.