[Maturation processes in the plasmalemma of erythroid cells]

Quantitative studies of the enucleating normoblast show that the plasmalemma envelope of the nucleus under extrusion and this of the nucleus that appear to be extruded bind more autologous IgG than the plasmalemma of the future reticulocyte. This finding explains the quick phagocytosis of the extruded nuclei by macrophages. In addition heaps of small vesicles free from haemoglobin are found at the enucleating normoblasts and at the reticulocytes. They bind cationized ferritin and autologous IgG. They are interpreted as segregation of constituents of the plasmalemma during red blood cell maturation.