[Model studies of erythrophagocytosis in vitro]

Macrophages of the RHS are important for the elimination of aged and altered erythrocytes. An increase in the membrane bound autologous IgG generates a recognition signal in the plasmalemma, which triggers the RBC-phagocytosis. The IgG-receptors are buried in the band 3 proteins of the membrane. Enzymatic degradations or conformational changes of the glycocalyx are accompanied by an expression of these receptors. Similar effects were obtained after alteration of the membrane skeleton (crosslinking of the spectrin). A clustering of IgG-receptors due to interaction of the denatured hemoglobin (Heinz-bodies) with the membrane seems to be unlikely. Exovesiculation represents a process of formation of an intact membrane structure. Prolonged stay of RBC in the spleen can induce membrane altering continued by increased IgG loading.