in vivo Ageing of human erythrocytes and cell-surface labeling by metaperiodate and sodium borotritide

Abstract

Young and old human erythrocytes, separated in vitro according to age, were labeled at the surface-sialic acid residues by sodium periodate and borotritide treatment. No qualitative difference was observed between the sialic acid derivatives of young- and old-erythrocyte membranes. The number of labeled residues was significantly decreased in the in vivo aged erythrocytes (12 +/- 2.8 X 10(6); n = 8) when compared to the young ones (19.4 +/- 2.8 X 10(6); n = 8). Analysis of the labeled glycoproteins by sodium dodecyl sulfate gel-electrophoresis showed that this decrease affects the PAS-1, PAS-4, PAS-2, and PAS-3 bands (glycophorins A and B) of the old-erythrocyte membranes.