Sanne de Bruin

124 Chapter 5 Abstract Glucose metabolism plays an important role in several aspects in the survival and functionality of erythrocytes. Storage of red cell concentrates (RCCs) is characterized by several changes including metabolic changes. This area of research has developed rapidly the last decade thanks to the emergence of new technologies. Besides aging during storage, aging under physiological conditions in vivo has been extensively stud- ied as well. These studies are mainly performed in the previous century while in the last decade more studies have been focusing on the biochemical changes during storage. Metabolic recovery from storage after transfusion is still a relatively unexplored field of research. Here we review the metabolic changes of erythrocytes and RCCs during physiological aging in vivo , during storage under blood bank conditions and during in vivo recovery from storage after transfusion. It is known that certain similarities between physiological aging and aging during stor- age exist but there are also quite some differences. During aging in vivo the glycolysis, Luebering-Rapoport shunt and pentose phosphate pathway (PPP) activity gradually decrease, whereas during storage metabolic fluxes are dependent on the choice of the additive solution. Under standard storage conditions adenine triphosphate (ATP) levels decrease rapidly and after two weeks of storage 2,3-diphosphoglycerate (2,3-DPG) is almost completely depleted. However, when alkaline additive solutions are used, ATP and 2,3-DPG levels can be maintained. Even though ATP and 2,3-DPG levels decrease rapidly during storage, it is known that these compounds are regenerated after trans- fusion. Data about PPP activity and GSH regeneration after transfusion is still lacking. The goal of this review is to summarize all current knowledge about this topic and to determine what knowledge is still lacking to set goals for future studies.