Abstract
Electron microscopic studies have been made on the ultrastructure of his-tiocytes of the subcutaneous connective tissue, in normal development of the cells and in various pathological conditions.
The histiocytes are morphologically characterized by predominance of the smooth components of the endoplasmic reticulum and abundance of cytoplasmic inclusion bodies. The cytoplasmic inclusion bodies observed in the present study can be divided into three types by their structure and origin. The first type called “H-granule (histiocyte granule)” in this study, is produced by accumulation of dense materials into the vesicles separated from the smooth-surfaced reticulum. The second type, “cytolysome”, results from sequestration of the focal cyto-plasmic degeneration. The third type, “phagosome”, originates in the vacuoles containing phagocytized materials. All these heterogenous inclusion bodies are considered to be involved in the digestion of materials of both exogenous and endogenous origins.
