Membrane elasticity of erythrocytes from normal and dystrophic mice

The membrane deformability of erythrocytes from normal and dystrophic mice was determined using a flow channel technique whereby erythrocytes attached to the floor of a parallel plate channel were deformed by fluid shear forces. A nonlinear stress-strain experimental behavior was observed for both populations of erythrocytes which was best described with a polynormal expression: tau s = a epsilon x + [b epsilon x3/2 epsilon x + 1]. A comprehensive statistical analysis of the data indicated that a large percentage of the variance of the data was due to the experimental design. Furthermore, the 2 populations of cells were different in terms of the strain-stress relationship which best fitted the data, i.e., epsilon x = alpha tau s + beta tau s2 + gamma tau s3. Up to a shear stress of 5.5 dyn/cm2, where 95% of the data points were found, the dystrophic erythrocytes were slightly but significantly more deformable than the normal erythrocytes.