[Origin and ultrastruct of peritoneal mononuclear phagocytes]

For the obtainment of reactive peritoneal macrophages was used an original technique by which small oval x-ray plates, wrapped up in viteline membrane were grafted into the abdominal cavity of white rats. As a result of the inflammatory reaction reactive cells were adhering to the membrane and among them macrophages of various stages of development as well. The membranes with the reactive cells which have been removed out at different periods of time (6, 12, and 24 h, 3, 5, and 7 d) were embedded in durcupan for electronmicroscopic examination. The ultrastructural organization of the macrophages having different stages of differentiation has been demonstrated by means of this technique. The problem concerning the origin of macrophages coming chiefly of the monocyte migration from blood circulation and passing through various transient forms was discussed as well as their ability to be transformed into giant cells, fibroblasts, mast cells, plasmocytes etc. in the course of the inflammatory reaction.