ELECTRON-MICROSCOPIC STUDIES ON PLASMA CELLES AND LYMPHOCYT ES IN HUMAN PALATINE TONSILS BY ULTA-THIN SLICE METHOD

Abstract

The fine structures of the plasma cells and lymphocytes found in the tissue of the human palatine tonsil were observed under an electron microscope by the aid of the ultra-thin slice method.The distribution of the plasma cells and lymphocytes coincided with and their shapes and contours were similar to the findings by the light microscope. However, as to the inner structures, new informations were obtained which could not even be imagined in the study by the light microscope.1. In both cells the nuclear membrane showed a double membraneous sturcture and the inside of the nucleus was filled with fine granular substance. In the plasma cell the granular substance was aggregated near the inner surface of the nuclear membrane, presenting a wheel-like appearance.However, typical wheel-like cells were extremely rare. In the lymphocyte the granular substance was found in the nucleus either dense or coarse. Unlike the plasm cell the substance was not aggregated inside the nuclear membrane.2. The Golgi apparatus showed a shape which was quite different from that observed by the light microscope. In the plasma cell the apparati were vacuoles of various size with elastic membranes or aggregates of membraneous structures and small vacuoles. It was concluded that this membraneous structure was essential for the Golgi apparatus. In the lymphocyte this apparatus was an aggregate of small granules with a simple structure.3. In both plasma cells and lymphocytes one or two centrioles were frequently found in the Golgi apparatus. Its solid structure was tubular and it was consistenty found.4. In the plasma cell dark and large granules were observed outside of the Golgi apparatus.It was supposed that these large granules were formed as the aggregates of the Golgi granules produced in the Golgi apparatus and sent into protoplasm.5. In the protoplasm of the plasma cell, flat or nearly flat cellules were richly found. In the lymphocyte no cellule was observed and only dark small granules were dispersed in the substrate of protoplasm.6. The mitochondria, like those in other cells, had clear border membranes. Inside, cristae mitochondriales of Palade were found between cellules and around the Golgi apparatus. In the lymphocyte they were found around the nucleus, near the nuclear recess and around the Golgi apparatus.7. In the plasma cell flat cellules wers found to participate in the formation of the Russel body. In the lumen solid protein sustances were richly observed. This seemed to offer strong evidence to support the theory of antibody production in the tonsil plasma cells.8. It is considerably difficult to relate the structure of a cell to its function. However, if the tonsil had immunological function, from the electron-microscopical structures, it would be inferred that the plasma cell plays a more important part than the lymphocyte.