MECHANISMS OF FREEZING INJURY TO BIOLOGICAL SYSTEMS.
LINDE DIV UNION CARBIDE CORP TONAWANDA N Y
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Biophysical and biochemical studies were conducted on red cells, liver mitrochondria, and various proteins to determine the mechanisms of freezing injury to biological systems. The working hypothesis formulated was that freezing resulted in molecular level dehydration leading to changes in proteins in terms of contractile behavior, enzymatic activity, interactions with water, and molecular size or shape. In general the evidence obtained, especially with proteins, and in particular by measurements of desorption-adsorption iso therms for water and gel chromatography showed no freeze related changes. Serum lipoproteins and frozen red cell membranes showed irreversibility in desorption-adsorption of water. Rat liver mitochondria were unaltered in contractile behavior by a variety of freezing conditions, some known to markedly alter function and permeability. Red cells RBC sustained cation composition changes K decrease Na increase and ATPase activity increase when subjected to dehydration without ice or increased salt exposure which resembled that found with freezing. Kinetics of salt injury to RBCs and the dependence on temperature was found inconsistent with salt as the only agent of freezing injury. Author
- Medicine and Medical Research