Deformation of human red cells in tube flow

Abstract

The flow behavior of single human red cells and rouleaux in plasma has been compared with that in viscous isotonic Ficoll and Dextran solutions, and in concentrated suspensions of reconstituted biconcave ghost cells. In the absence of particle interactions, marked deformation of red cells was not evident in plasma at shear stresses of 3 dyne cm⁻², even though the cells migrated inwards from the tube wall, a property of deformable particles such as previously observed with liquid droplets. In viscous media at shear stresses above 5 dyne cm⁻², the cells were deformed into ellipsoid-like structures but with the dimple still present.

In contrast, at volume concentrations above 30 per cent in plasma, deformation of erythrocytes and rouleaux was observed at shear stresses as low as 0.07 dyne cm⁻². This effect is due to crowding of the particles.