Phosphoenolypyruvate (PEP) Effects on Fresh and Stored Red Blood Cells 1 2

Abstract

Abstract

The present studies were performed to evaluate the effects of phosphoenolpyruvate (PEP) on fresh and stored red blood cells as a possible adjunct to citrate phosphate dextrose (CPD) for preservation of blood. Red cell concentrates prepared from fresh blood drawn from human volunteers were incubated with CPD alone or CPD containing PEP. At 37° and an initial pH of less than 6.2, a significant increase in 2,3-DPG and maintenance of ATP were observed. A dose-dependent increase in 2,3-DPG was noted in blood incubated in CPD-PEP from 13 to 52 mM. 2,3-DPG did not change during incubation at either 4° or 25°. A significant increase in ATP was observed at 25°; ATP remained unchanged at 4° and 37°. Storage related depletion of 2,3-DPG and ATP was reversed by PEP incubation (26 mM) even when blood was stored for 42 days in CPD. In fact, 2,3-DPG levels two or three times greater than normal were regularly observed. The persistence, in vivo, of the PEP-induced increase in 2,3-DPG and P₅₀ was demonstrated by 33% exchange transfusions in rats with homologous blood treated for 4 hr with 26 mM PEP. Unlike other preservation additives, incubation with PEP results in a dramatic increase in 2,3-DPG without depletion of ATP, a property which is maintained in vivo. Evidence shows that PEP should be considered as a potential adjunct to conventional blood preservation systems.