Comparative rheology of nucleated and non-nucleated red blood cells. I. Microrheology of avian erythrocytes during capillary flow.

Deformation and dynamic flow behaviour of nucleated duck erythrocytes were compared to those of nonnucleated human cells during steady flow (at wall shear stresses up to 3 N.m-2) through glass capillaries (diameter between 5 micrometer and 12 micrometer). While the deformation process of both cell species is qualitatively similar, significant quantitative differences demonstrate a lower deformability of the nucleated erythrocytes. In comparison to human cells, the avian red cells exhibit significantly lower stability of orientation during capillary flow. Viscometric measurements show that, in contrast to human red cell suspensions, the relative viscosity of nucleated cell suspensions does not decrease with increasing suspending medium viscosity. The results indicate that the hydrodynamic disturbance caused by avian erythrocytes in the flow of the suspending fluid is more pronounced than that of the mammalian cells. This is due to their lower ability to adapt to local shear forces.