Температура и осмолярность как факторы, определяющие устойчивость эритроцитов млекопитающих к гипертоническому шоку

Abstract

The effect of initial state of mammalian erythrocytes modified with temperature and medium osmolarity on the sensitivity of cells to hypertnic shock (4.0 M NaCl) was studied. Human, bovine, equine, rat’s erythrocytes were pre-dehydrated to form various initial states of cells in respect of the following effect of hypertonic shock. With increasing salt concentration in the preincubation medium the reduction of hypertonic hemolysis of the cells with a following increase occurs. The states of erythrocytes, for which the minimal and maximal rates of hemolysis are characteristic in 4.0 M NaCl, were called as «stable» and «metastable», respectively. It has been revealed that when increasing the temperature within the range from 0 to 37°C there is observed a rise in hypertonic hemolysis rate of erythrocytes of all the investigated mammals (human, bull, horse, rat) transferred from 0.15 to 4.0 M NaCl. Herewith for bovine erythrocytes an in increased in hypertonic hemolysis rate is characteristic with a temperature rise (from 0 to 37°C) of about 4 times, while for human cells, those of horse and rat this makes in 1.2-2.0 times. Temperature dependence of hypertonic hemolysis of stable human erythrocytes (0.4  4.0 M NaCl) was more manifested if compared with the control and metastable cells (0.8 4.0 M NaCl). For stable equine erythrocytes (0.4  4.0 M NaCl) the severity of hemolytic damage is observed only at the temperatures higher than 15°C. For bovine erythrocytes the temperature dependence of hypertonic hemolysis is absent in the case when the cells form a stable state (1.0 ® 4.0 M NaCl). Moreover, for these cells no distinct zone of «metastability» was found. In the media containing 2.0 M NaCl, there is observed just the tendency of the hemolysis rise if compared to the medium of 1.0 M NaCl at 37°C. It should be noted that for the rat cells the minimal value of hypertonic hemolysis at 37 and 0°C is observed when erythrocytes are dehydrated in different media (0.3 M and 0.4 M NaCl). Erythrocytes are considered as stable, when dehydrated in 0.3 M NaCl, because their damage rate in 4.0 M NaCl is lower than the hemolysis values of the control and «metastable» cells within the whole range of the temperatures studied. Temperature dependencies of hypertonic hemolysis of the control and stable rat’s erythrocytes (0.3 ® 4.0 M NaCl) were slightly manifested while the injury of metastable cells (0.6 ® 4.0 M NaCl) significantly enhanced within the temperature range of 0-25°C. It has been established that the hemolysis rate in 4.0 M NaCl of stable erythrocytes of all the investigated mammals is lower if compared with the same indices of the control and metastable cells at all the values of temperatures (0, 15, 25 è 37°Ñ). Thus the resistance of mammalian erythrocytes to hypertonic shock is determined by initial state of cells which is formed as a result of combined effect of temperature and medium osmolarity. The findings are discussed from the point of view of forming the hemolytic pore in erythrocyte membrane when altering the medium osmolarity and temperature.