[Techniques for experimental and clinical studies of erythrocyte deformability]

Deformability is an important property of red blood cells and ensures the efficiency of their transport in the microcirculatory vascular system, as well as tissue oxygenation. A study of erythrocyte deformability uses different methods: filtration through about 5.0-microm pores, laser difractometry techniques and a focus of attention has recently been on a procedure for measuring the deformability of erythrocytes in a flow microchamber. The authors have developed a procedure for the recording of erythrocyte deformability and for the computer-aided treatment of an obtained image to have an accurate quantitative assessment of this important microrheological property of the cells. Comparison of the suspension viscosity of erythrocytes at high shift rates and the erythrocyte lengthening index (ELI) in the flow microchamber yielded a high correlation (p = -0.917; p < 0.01). That of ELI in the fractions of young and old cells also supported the high sensitivity of the procedure. Analysis of changes in the degree of erythrocyte deformability (in accordance with ELI), by applying three values of shift strain, revealed an almost linear relationship of the lengthening of fixed cells to the applied shift pressure. The known rheomodulator pentoxiphylline caused a significant erythrocyte deformability increase that was recorded by both methods (in the flow microchamber and at viscosimetry of erythrocyte suspensions with the hematocrit being equal to 40%). Thus, findings suggest that the method for the recording of erythrocyte deformability in the flow microchamber with the computer-aided analysis of images allows one to adequately measure this property of red blood cells.