Changes in carbohydrate content of surface membranes of human erythrocytes during ageing.

The carbohydrate content (neutral hexoses, fucose, sialic acid, and hexosamine) of human erythrocytes is significantly higher in young than in old erythrocytes. The differences observed in the carbohydrate content of surface glycopeptides, obtained after incubation with either Pronase or trypsin, is still more striking, suggesting important modifications of the carbohydrate moeties of the erythrocyte membrane during in vivo ageing.