The flow behavior of lysolecithin-induced echinocytes 1

Lysolecithin is formed by enzymatic processes in the blood plasma both in vivo and in vitro. Erythrocyte suspensions which are treated with lysolecithin, have a higher viscosity than normal erythrocytes. At high shear rates this may be attributed to a reduced deformability of these cells. At shear rates below 10 s⁻¹, however, these erythrocytes maintain their resting shape (which is that of a spiculated sphere) and their viscosity is 8 times higher than that of aldehyde-hardened erythrocytes. It is therefore concluded that the reduced deformability of lysolecithin-treated erythrocytes is not the cause of their high viscosity at low flow velocities. The results of this paper suggest that lysolecithin-treated red cells have an increased functional volume due to the immobilization of fluid between their spicules. Furthermore the lysolecithin-treated erythrocytes, despite their sphered shape can attach to each other when the suspending medium contains long-chain molecules. Both the increased functional volume and the attachment of the cells can explain the high viscosity values at the lower shear rates.