Physical-chemical basis of the protection of slowly frozen human erythrocytes by glycerol
One theory of freezing damage suggests that slowly cooled cells are killed by being exposed to increasing concentrations of electrolytes as the suspending medium freezes. A corollary to this view is that protective additives such as glycerol protect cells by acting colligatively to reduce the electrolyte concentration at any subzero temperature. Recently published phase-diagram data for the ternary system glycerol-NaCl-water by M.L. Shepard et al. (Cryobiology, 13: 9-23, 1976), in combination with the data on human red cell survival vs. subzero temperature presented here and in the companion study of Souzu and Mazur (Biophys. J., 23: 89-100), permit a precise test of this theory. Appropriate liquidus phase-diagram information for the solutions used in the red cell freezing experiments was obtained by interpolation of liquidus data of Shepard and his co-workers. The results of phase-diagram analysis of red cell survival indicate that the correlation between the temperature that yields 50% hemolysis (LT/sub 50/) and the electrolyte concentration attained at that temperature in various concentrations of glycerol is poor. With increasing concentrations of glycerol, the cells were killed at progressively lower concentrations of NaCl. For example, the LT/sub 50/ for cells frozen in the absence of glycerol corresponds to a NaCl concentration of 12 weight percent (2.4 molal), while for cells frozen in 1.75 M glycerol in buffered saline the LT/sub 50/ corresponds to 3.0 weight percent NaCl (1.3 molal). The data, in combination with other findings, lead to two conclusions: (a) The protection from glycerol is due to its colligative ability to reduce the concentration of sodium chloride in the external medium, but (b) the protection is less than that expected from colligative effects; apparently glycerol itself can also be a source of damage, probably because it renders the red cells susceptible to osmotic shock during thawing.
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- OSTI ID:
- 6790054
- Journal Information:
- Biophys. J.; (United States), Vol. 23:1
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ERYTHROCYTES
HEMOLYSIS
SURVIVAL CURVES
FREEZING
BIOLOGICAL EFFECTS
GLYCEROL
TEMPERATURE DEPENDENCE
SODIUM CHLORIDES
LOW TEMPERATURE
MAN
PHASE DIAGRAMS
WATER
ALCOHOLS
ALKALI METAL COMPOUNDS
ANIMALS
BIOLOGICAL MATERIALS
BLOOD
BLOOD CELLS
BODY FLUIDS
CHLORIDES
CHLORINE COMPOUNDS
DIAGRAMS
DISEASES
HALIDES
HALOGEN COMPOUNDS
HYDROGEN COMPOUNDS
HYDROXY COMPOUNDS
LYSIS
MAMMALS
ORGANIC COMPOUNDS
OXYGEN COMPOUNDS
PATHOLOGICAL CHANGES
PRIMATES
SODIUM COMPOUNDS
VERTEBRATES
550300* - Cytology
550900 - Pathology
551000 - Physiological Systems