Cytochemical and cellbiological investigations of the signal function of the erythrocyte plasmalemma--the membrane structure as code for cell life span.

The erythrocyte membrane was characterized with regard to its alteration of different degrees. A very important process of the membrane alteration is the expression of IgG receptor sites, which is connected with the binding of autologous IgG at the membrane. Several detection methods for membrane bound IgG were described: immunocytochemical techniques (Anti IgG--Anti Ferritin-sandwich technique, Anti IgG-Protein A-Gold- and the Silver enhancement technique), Antiglobulin agglutination test (Coombs test) and erythrocyte-macrophage test. Moreover, the topo-optical toluidine blue reaction and the ultra-histochemical NAD(H) oxidase reaction were checked to characterize the erythrocyte-macrophage interaction. Finally, the microvesiculation is understood as special form of the erythrocyte membrane disintegration, which is connected with a remodelling of an intact plasmalemma. The findings presented here summarize the fact that the membrane associated IgG regulates an immune-signal for the elimination of the erythrocytes in the Reticulo-Histiocytic-System in vivo and in vitro. Therefore, the structural integrity of the erythrocyte plasmalemma is the code for the cell life span.