Proteolytic enzymes marking of malignant lymphoblasts, study of the L5178Y murine lymphoma

The bovine pancreatic inhibitor of trypsin (trasylol, Bayer) (T) and the soy bean trypsin inhibitor (SBI) were coupled with peroxidase (P). With each one of these coupling products (T and P and SBI and P) the cell distribution of proteolytic enzymes (PE) of ascitic cells of L5178Y murine lymphoma, was localized. The reactions were developed by means of Karnowsky's reaction with diaminobenzidine and H2O2. The preparations were observed under light and electronic microscopy. It was found that L5178Y cells contain intracellular PE in granules measuring 0.1 to 0.8 min diameter, and superficial PE that form a continuous layer of 80 to 120 nm over the cell surface. Superficial PE were not identified in 20 per cent of L5178Y cells, while in every case intracellular granules were found. Both the macrophages and the polimorphonuclear cells present in the ascitic fluid contained intracellular PE granules measuring 0.05 to 0.4 micron in diameter, and did not contain superficial PE.