ABSTRACT
A topographical image of individual erythrocytes of the ground squirrel Citellus undulatus Pallas, in unfixed unstained smears was first obtained by scanning probe microscopy for two states of the animal: hibernation and the active state. The scannig of single discocytes, i.e. erythrocytes having a typical discal form, was fulfilled. For the active male, the diameter of the discocyte was found to be approximately 6500 nm. For the hibernating female, the diameter is approximately 6000 nm. According to the data of light microscopy, the discocyte diameters are: 6610 +/- 100 nm for the active state of animal and 6430 +/- 160 nm for the hibernating state.
Subject(s)
Erythrocytes/cytology , Hibernation , Sciuridae/blood , Animals , Cell Size , Female , Male , Microscopy, Electron, ScanningABSTRACT
Taking into account the van't Hoff's law the rates of relative erythrocyte hemolysis in ground squirrel Citellus undulatus Pallas during different phases of hibernation were first studied by the method of acid erythrograms with some modifications. The temperature of the erythrogram registration (8 degrees C) models the body temperature in hibernation, and temperature of 35 degrees C, corresponds to the body temperature of the awakened ground squirrel. The positions of the erythrogram maxima for the ground squirrel during short-term arousal and during hibernation coincide for each temperature studied: 8 or 35 degrees C. Therefore, the increase in HCl concentration at 8 degrees C reflects an increase in the stability of erythrocyte membranes or a decrease in the rate of relative hemolysis for the ground squirrel during hibernation. Thus, the adaptive response of erythrocytes in hibernating ground squirrel is revealed. The correlation of the rates of physicochemical processes in vitro with the rates of physiological ones in vivo is shown using the ratio of the rates mentioned above for the short-term arousal and for hibernation. First the physicochemical way of cold adaptation due to the van't Hoff's law is proved.
Subject(s)
Adaptation, Physiological , Cold Temperature , Hibernation/physiology , Sciuridae/physiology , Animals , Body Temperature Regulation , Erythrocyte Membrane/physiology , HemolysisABSTRACT
Electrophoretic mobility of Escherichia coli cells exposed to various doses of UV-radiation was investigated. The method of free flow electrophoresis was used to study a correlation between membrane protein charge and cell surface electric charge. The change in the cell surface charge and electrophoretic motility was associated with the damage to membrane proteins and the survival of UV-irradiated bacteria.
