The effect of cell swelling rate on the permeability and mechanical properties of the erythrocyte membrane.
A theoretical C-state model based on a thermodynamic equilibrium between water and chloride ions was used to calculate the cell volume of erythrocytes in hypotonic NaCl or sucrose media from information on the intracellular concentrations of cytoplasmic compounds and the area and volume distributions of erythrocytes in an isotonic reference state. Using various assumptions regarding prelytic potassium release and the corresponding sodium influx into cells swollen to a spherical mode, theoretical curves for the total amount of potassium released and cells haemolyzed as a function of the ambient osmotic pressure were generated and compared with the experimental results. The mechanical properties of the cell membrane in NaCl media during rapid water influx do not allow the cells to reach a spherical shape without membrane damage, which makes the membrane permeable to cations and also to haemoglobin. Reduction of the swelling rate diminishes the membrane injury and increases the protective role of potassium efflux in preventing haemolysis, but the cell membrane still is injured during sphering.
D002463:Cell Membrane Permeability; D004910:Erythrocyte Membrane / Q000187:drug effects / Q000502:physiology* / Q000648:ultrastructure; D006801:Humans; D009994:Osmolar Concentration; D012965:Sodium Chloride / Q000494:pharmacology; D013395:Sucrose; D013816:Thermodynamics
D012965:Sodium Chloride; D013395:Sucrose