Viscoelastic study of aggregation of red blood cells 1

Abstract

The flow curves of rabbit blood, human fetal blood, and human adult blood show no hysteresis, a little hysteresis and considerable hysteresis, corresponding to their capacity of forming rouleaux. After the cessation of the steady flow, which was used to remove the original aggregation of cells, the time variations of the rigidity modulus G′ and the loss modulus G″ were determined at 1 Hz. For rabbit blood, almost no time change for G′ and G″ and no erythrocyte sedimentation was observed. For human adult blood, G′ and G″ first increased to a maximum value and then decreased. The rate of erythrocyte sedimentation was correlated to the rates of increase and decrease of G′ and G″. These observations were accounted for by considering the change of structure of blood: i.e. the formation of rouleux, the association of rouleux, and the formation of nonhomogeneous structure.