Relative contributions of the fraction of unfrozen water and of salt concentration to the survival of slowly frozen human erythrocytes
As suspensions of cells freeze, the electrolytes and other solutes in the external solution concentrate progressively, and the cells undergo osmotic dehydration if cooling is slow. The progressive concentration of solute comes about as increasing amounts of pure ice precipitate out of solution and cause the liquid-filled channels in which the cells are sequestered to dwindle in size. The consensus has been that slow freezing injury is related to the composition of the solution in these channels and not to the amount of residual liquid. The purpose of the research reported here was to test this assumption on human erythrocytes. Two solutes were used here: NaCl and the permeating protective addivitve glycerol. Human red cells were suspended in solutions with weight ratios of glycerol to NaCl of either 6.42 or 11.26, where the concentrations of NaCl were 0.6, 0.75, 1.0, 2.0, 3.0, or 4.0 times isotonic. Samples were then frozen to various subzero temperatures, which were chosen to produce various molalities of NaCl (0.24-3.30) while holding the fraction of unfrozen water constant, or conversely to produce various unfrozen fractions (0.03-0.5) while holding the molality of salt constant. (Not all combinations of these values were possible). The following general findings emerged: (a) few cells survived the freezing of > 90% of the extracellular water regardless of the salt concentration in the residual unfrozen portion, (b) When the fraction of frozen water was < 75%, the majority of the cells survived even when the salt concentration in the unfrozen portion exceeded 2 molal. (c) Salt concentration affected survival significantly only when the frozen fractionlay between 75 and 90%
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- DOE Contract Number:
- W-7405-ENG-26
- OSTI ID:
- 5632121
- Journal Information:
- Biophys. J.; (United States), Vol. 36:3
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ERYTHROCYTES
FREEZING
HEMOLYSIS
INJURIES
SOLUTIONS
SURVIVAL CURVES
BIOLOGICAL EFFECTS
ANIMAL CELLS
EXPERIMENTAL DATA
GLYCEROL
SODIUM CHLORIDES
ALCOHOLS
ALKALI METAL COMPOUNDS
BIOLOGICAL MATERIALS
BLOOD
BLOOD CELLS
BODY FLUIDS
CHLORIDES
CHLORINE COMPOUNDS
DATA
DISPERSIONS
HALIDES
HALOGEN COMPOUNDS
HYDROXY COMPOUNDS
INFORMATION
LYSIS
MATERIALS
MIXTURES
NUMERICAL DATA
ORGANIC COMPOUNDS
PATHOLOGICAL CHANGES
SODIUM COMPOUNDS
550300* - Cytology