Altered intracellular purine nucleotides in gamma-irradiated red blood cell concentrates

Background and Objectives Gamma irradiation at a dose of 30 Gy induces deterioration of erythrocytes, resulting in storage lesions that significantly shorten the shelf-life of packed red cell concentrates (RCCs). The aim of the present study was to investigate the effect of gamma irradiation on intracellular purine nucleotides of red blood cells during storage. Materials and Methods Three-day-old leucocyte-depleted saline-adenine-glucose-mannitol (SAGM)-preserved RCCs, obtained from the Blood Service of the Austrian Red Cross, were gamma irradiated with 30 Gy. Samples were taken on days 1, 2, 3 and 7 after irradiation and subsequently at weekly intervals up to the end the of shelf-life (day 39 after irradiation) and were investigated for the K+ and Na+ content in the supernatant, for intracellular concentrations of ATP, ADP, ITP, IDP, GTP and GDP of erythrocytes, and for haemolysis. Results Within the first 24 h after gamma irradiation, no metabolic or biochemical changes were detectable in the RCCs. The K+ concentration in the supernatant increased after 24 h, while the Na+ concentration decreased in irradiated units and this ion disequilibrium persisted until the end of the shelf-life. After an initial increase of intracellular ATP, ADP and GTP during the first week of storage, the intracellular concentrations of ATP, ADP, GTP and ITP decreased, while IDP increased. The decrease of ATP and ADP was found to be more pronounced in irradiated units. At the end of the shelf-life, the ATP, GTP and ITP concentrations of irradiated RCCs had decreased to < 10% of the initial level and the critical threshold of 0.8% haemolysis was reached. Conclusion Gamma irradiation of SAGM-preserved RCCs leads to serious deterioration of the purine nucleotide metabolism of erythrocytes during storage, which can reduce the in vivo recovery of the transfused red cells.