Effect of hyperthermia and ionizing radiation on the erythrocyte membrane.
Spin-label studies of the effects of hyperthermia on the erythrocyte membrane revealed a decrease in the fluidity of lipids and changes in the state of membrane proteins. The rate of haemolysis in iso-osmotic glycerol solution was increased. Changes of most of the parameters studied when plotted in Arrhenius coordinates revealed a discontinuity (critical hyperthermic transition in the membrane) between 46 and 50 degrees C. Studies of the combined action of ionizing radiation (100 Gy) and hyperthermia (43 degrees C) showed the same direction of changes for (Na-K-Mg)-ATPase activity and spectra of membrane-bound maleimide spin label for both agents, but the additivity of changes depended on the parameter studied.
D000818:Animals; D002417:Cattle; D003037:Cobalt Radioisotopes; D003497:Cyclic N-Oxides; D004578:Electron Spin Resonance Spectroscopy; D004910:Erythrocyte Membrane / Q000201:enzymology / Q000528:radiation effects*; D004912:Erythrocytes / Q000528:radiation effects*; D005720:Gamma Rays; D006461:Hemolysis; D006358:Hot Temperature; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism; D013113:Spin Labels
D003037:Cobalt Radioisotopes; D003497:Cyclic N-Oxides; D013113:Spin Labels; C017480:4-maleimido-2,2,6,6-tetramethylpiperidinooxyl; C003028:N-(1-oxyl-2,2,6,6-tetramethyl-4-piperidinyl)iodoacetamide; C024283:12-doxylstearate methyl ester; C030704:magnesium sodium potassium ATPase; D000254:Sodium-Potassium-Exchanging ATPase