Temperature-dependent changes in erythrocytes' cytosol state during natural and artificial hypobiosis.

At present, the question of how the structural state of the erythrocyte cytosol is arranged to maintain essential permeabilities successfully both at normal temperature and during periods with a significant body temperature reduction during hypobiosis remains unanswered. In the present work, we performed comparative investigations of temperature-dependent changes in the cytosol state of erythrocytes from animals subjected to natural (winter hibernating ground squirrels) or artificial hypobiosis. The cytosol state was evaluated by the ESR method of spin probes (TEMPON) within the temperature range of 0-50 degrees C. Erythrocyte resistance to acid hemolysis, which is limited by the permeability of membranes for protons and the state of the anion channel, were determined using the method described by Terskov and Getelson [Biofizika 2 (1957) 259]. A change in cytosol microviscosity of erythrocytes was found as well as a temperature-dependent increase in acid resistance of erythrocytes. Our investigations allow us to conclude that physiological changes occurring in a mammalian organism during natural and artificial hypobiosis are accompanied by structural modifications of the erythrocyte cytosol. The temperature range where these modifications are observed (8, 15, 40 degrees C) suggests that the most probable modifying link is spectrin and/or the sites of its interaction with membrane. The interaction of cytoskeletal components with the cell membrane plays a key role in regulation of membrane permeability, suggesting an important role of this interaction in the adaptive reactions of erythrocytes.

[The ultrastructural and dynamic characteristics of erythrocyte membranes. The effect of the physiological status and temperature]. / Ul'trastrukturnye i dinamicheskie kharakteristiki membran éritrotsitov. Vliianie fiziologicheskogo sostoianiia i temperatury.

Erythrocyte membranes of ground squirrels taken from hibernating, awakening and active animals with the body temperatures of 4, 30 and 36 degrees C, respectively, have been shown by freeze-fracture technique to differ in morphology of the PF surface, density and distribution patterns of intramembrane particles. The ultrastructural changes in membrane caused by temperature were confirmed by the data on alterations of dynamics parameters of the lipid bilayer and spectral characteristics of membrane proteins.