Conductometric study of erythrocytes during centrifugation. II. Erythrocyte deformability.

Erythrocyte deformability was studied by continuous reading of sediment conductance during centrifugation. The decrease in sediment conductivity during centrifugation reflects erythrocyte deformation in the pellet. The degree of erythrocyte deformation depends on the duration of centrifugation and the magnitude of centripetal acceleration. When constant centrifugal force is applied over an extended period of time, a gradual decrease in pellet conductivity occurs. Stepwise enhancement of centripetal acceleration during centrifugation induces a rapid increase in erythrocyte deformation. After centrifugation, the relaxation of erythrocyte deformation is observed. However, the relaxation and the recovery of cell shape are incomplete. The difference in compressibility of previously centrifuged and noncentrifuged cells demonstrates that centrifugation causes irreversible alteration in erythrocyte deformability. The results show that the time-dependent resistance of erythrocyte sediment during centrifugation may serve as a useful index for the kinetics of erythrocyte deformation.