Structural modifications in membrane glycoproteins during the erythrocyte life-span.

Erythrocyte membrane glycoproteins undergo various types of modification during the life of the cell in the circulation; when only sialic acid is removed, the younger red cells can be repaired in the liver and return to the circulation. Otherwise, when an autolytic mechanism removing a sialopeptide becomes active as a consequence of the metabolic impairment of the cell, the erythrocyte is probably trapped by the hemocatheretic organs and destroyed.