Studies in red blood cell preservation. 2. Comparison of vesicle formation, morphology, and membrane lipids during storage in AS-1 and CPDA-1

The changes in morphology, the quantitative changes in membrane lipids and the shedding of exocytic vesicles by red blood cells (RBC) stored for 42 and 56 days in AS-1 and CPDA-1 were compared. RBC stored in AS-1 shed significantly less vesicle membrane cholesterol, phospholipid and protein and maintained better morphology scores. RBC membrane cholesterol remained higher after 56 days in AS-1 than in CPDA-1. The data suggest that during the first weeks of storage cholesterol is lost from the RBC membrane followed by a larger release of phospholipids accompanied by alterations in the phosphoinositides. The shedding of exocytic vesicles appears to be secondary to the changes in morphology resulting from the perturbation of the membrane lipids.