Gamma-Ray-Irradiated Red Blood Cells Stored in Mannitol-Adenine-Phosphate Medium: Rheological Evaluation and Susceptibility to Oxidative Stress

<abstitle>AbstractBackground and Objectives: To evaluate the rheological properties and the oxidative susceptibility of γ-ray-irradiated red blood cells (RBCs). Materials and Methods: RBCs in mannitol-adenine-phosphate (MAP) medium were irradiated with 35 Gy and stored at 4°C for 4 weeks. The deformability of the RBCs was examined under shear flow in relation to the morphological and biochemical changes. The RBCs were further exposed to 1 mM FeSO₄ and 5 mM ascorbate to examine the oxidative susceptibility. Results: The RBC deformability was decreased during storage, and the impairment was further enhanced by the irradiation, which promoted cell shrinkage and intracellular hemoglobin condensation accompanying potassium loss. Lipid peroxidation and protein aggregation of the RBC membrane as well as echinocytosis were not enhanced by the irradiation. The exposure to free iron did not stimulate the oxidation of the irradiated RBC membrane. Conclusion: The decreased deformability of γ-ray-irradiated RBCs in MAP medium was mainly induced by dehydration due to potassium loss, and the membrane lipids and proteins were stably preserved against oxidative stress.Copyright © 2000 S. Karger AG, Basel