Gamma-ray-irradiated red blood cells stored in mannitol-adenine-phosphate medium: Rheological evaluation and susceptibility to oxidative stress

Background and Objectives: To evaluate the rheological properties and the o xidative susceptibility of gamma-ray-irradiated red blood cells (RBCs), Mat erials and Methods: RBCs in mannitol-adenine-phosphate (MAP) medium were ir radiated with 35 Gy and stored at 4 degrees C for 4 weeks. The deformabilit y of the RBCs was examined under shear flow in relation to the morphologica l and biochemical changes. The RBCs were further exposed to 1 mM FeSO4 and 5 mM ascorbate to examine the oxidative susceptibility, Results: The RBC de formability was decreased during storage, and the impairment was further en hanced 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 th e oxidation of the irradiated RBC membrane. Conclusion: The decreased defor mability of gamma-ray-irradiated RBCs in MAP medium was mainly induced by d ehydration due to potassium loss, and the membrane lipids and proteins were stably preserved against oxidative stress. Copyright (C) 2000 S. Karger AG . Basel.