Affiliations: Department of Physiology, School of Medicine, Ehime University Shigenobu, Onsen‐gun, Ehime 791‐0295, Japan | Department of Transfusion Information, The Japanese Red Cross Central Blood Center, Hiroo 4‐1‐31, Shibuya‐ku, Tokyo 150‐0012, Japan
Note: [] Correspondence to: Prof. Nobuji Maeda, Department of Physiology, School of Medicine, Ehime University, Shigenobu, Onsen‐gun, Ehime 791‐0295, Japan. Tel.: +81 89 960 5244; Fax: +81 89 960 5246; E‐mail: nmaeda@m.ehime‐u.ac.jp.
Abstract: X‐ray irradiation of blood is an effective way to prevent transfusion‐associated graft‐versus‐host disease. Red blood cells (RBCs) from normal donors suspended in mannitol‐adenine‐phosphate (MAP) medium were irradiated with X‐ray of 15 and 35 Gy in minimum dose. The change of deformability of the RBCs during storage at 4°C for 4 weeks was examined under shear stress of 13–130 dyn/cm^2 using a rheoscope, in relation to the hematological and biochemical properties. (1) The deformability of RBCs was decreased during the storage, and it was further decreased by the irradiation. In addition, the number of undeformable RBCs against a given shear stress increased after the irradiation. (2) The cell volume gradually decreased, while the intracellular hemoglobin concentration increased. These changes were accelerated by the irradiation. The echinocytic transformation during the storage was not accelerated by the irradiation. (3) The content of aggregated proteins reducible with beta‐mercaptoethanol in RBC membrane increased during the storage, but was not increased by the irradiation. Membrane lipid peroxidation was not increased during the storage and by the irradiation. (4) Leakage of potassium ions from RBCs during the storage was accelerated by the irradiation. In conclusion, shear‐induced deformation of RBCs stored in MAP medium was impaired by X‐ray irradiation, mainly due to dehydration caused by excess leakage of potassium ions from RBCs.
