Rheology of shape-transformed human red cells

Abstract

Using human RBC suspended in buffer, the rheologic effects of the discocyte-ecllinocyte shape transformation have been studied via cone-plate and Couette viscometry. An isovolumic shape change, induced by nitrophenols or a substituted benzoate, results in altered flow behavior: 1) low shear rate viscosity is increased in relation to the degree of echinocyte formation; 2) at high shear rates, the rheologic behavior, regardless of initial cellular morphology, is nearly identical to normal, biconcave RBC. Restoration of the biconcave shape, in the presence of the echinocytic agent, returns the rheologic behavior toward control over the entire range of shear rates. The rheologic changes appear to be related to increased cell-cell interaction enhanced by the echinocyte form. Correlations with other studies describing RBC shape changes are discussed.