Role of the plasma membrane in the development of thermotolerance in mammalian erythrocytes

Abstract 1. 1. Using electron spin resonance (ESR) and fluorescence spectroscopy, changes in the structure of thermotolerant erythrocytes have been studied. 2. 2. Heat and SH-reagents (diamide, disulfiram) caused alterations in the level of SH groups, in the content of membrane cytoskeletal proteins and the conformation of proteins in thermotolerant cells. 3. 3. The fluidity of membrane lipids was decreased at the surface of lipid bilayer in heat and diamide thermotolerant cells only. 4. 4. In the presence of DNP, no significant changes in the organization of membrane lipids and proteins of tolerant cells were observed. 5. 5. These results suggest that the plasma membrane may be responsible for the development of thermotolerance in enucleated erythrocytes, independent of other mechanisms.