Effect of red cell age on vesiculation in vitro.

Microvesiculation of RBC occurs in vivo and during in vitro storage. Vesiculation of young and old populations of RBC was measured under blood bank conditions. The RBC in whole units of blood were divided by density into two approximately equal fractions in a closed system. After storage for 35 d the haemoglobin-containing vesicles were quantitatively recovered. Quantitation of protein, cholesterol and phospholipids showed significantly larger amounts in the vesicles shed by the younger RBC. Otherwise vesicles shed by the two populations of RBC did not differ.