[Effect of reduced and oxidized glutathione on physico-chemical properties of erythrocyte membranes].

The parameters describing the structural and functional state of membranes depending on the level of reduced glutathione in erythrocytes were studied. It was shown, that the decrease in the concentration of reduced intracellular glutathione in erythrocytes upon metabolic depletion (prolonged incubation of cells at 37 degrees C in the absence of glucose) or a rapid irreversible depletion of glutathione with 1-chloro-2,4-dinitrobenzene enhances lipid peroxidation processes in membranes, inhibits the membrane-bound NAD.H methemoglobin reductase activity and decreases the intensity of 1,6-diphenyl-1,3,5-hexatrien fluorescence.

[Parameters of hemolysis by sodium dodecyl sulfate as an indicator of the structural states of erythrocyte membranes].

The relationship between the parameters (percentage and rate) of hemolysis by sodium dodecyl sulfate and the time of incubation of human erythrocyte suspensions in glucose-free medium at 37 degrees C was studied. The polyphasic changes in the parameters were found, which depend on the mode of pretreatment: ATP depletion by iodoacetate, heat denaturation of spectrin, and treatment of cells by valinomycin. It was found that the percentage and rate of detergent hemolysis do not always change in parallel.

[Oxidation of membrane proteins and modification of erythrocyte surface characteristics].

It is shown that the oxidation of membrane protein SH-groups of human erythrocytes by diamide leads to the intensification of vesiculation and the formation on the cell surface of "senescent antigens". These processes were studied during prolonged incubation of erythrocytes at 37 degrees C in the absence of glucose. It was found that the formation of vesicules in ATP-depleted cells correlated with the appearance of "senescent antigens" (r = 0.

[Heterogeneity of pores formed in erythrocyte membrane by lipophilic hemolysins].

Concentration dependences of the rate of hemolysis are studied for ascorbic acid, sodium dodecylsulfate, triton X-100, ethyl and butyl alcohols. The double logarithmic plot of this dependence for ascorbic acid presents the straight line with the slope (n) of 2, meaning that two hemolytic molecules are necessary for the formation of one pore in the membrane. Other hemolysins are characterized by the curves with n changing from 2 to 24 as hemolysin concentration increases.

[Autohemolysis of human erythrocytes in the temperature range 4-37 C].

It is shown that the value of activation energy of red blood cells autohemolysis in temperature range of 4 + 37 degrees C is considerably smaller than that at t > 37 degrees C and is about 50 kJ/mol in isotonic saline buffer, pH 7.4. This means that the change of limiting stage of hemolysis occurs at 37 degrees C.