Studies of factors regulating the ageing of human erythrocytes-IV. Influence of physiological proteinase inhibitors

1. 1. The release of sialoglycopeptides from the membrane of erythrocytes incubated at 37°C in a physiological, aproteic solution containing divalent cations, but without glucose, can be correlated with the number of polymorphonuclear leukocytes (PMNL). 2. 2. Erythrocytic glycoproteins emerging in the outer environment can be cleaved by neutral proteinases unless natural inhibitors are present. 3. 3. Among the inhibitors: α2-macroglobulin, α1-antitrypsin and α2-antiplasmin, tested within the physiological range of concentrations, the α2-macroglobulin inhibits proteolysis very effectively. © 1981.