PubMed · 5775460
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F D Hart. 1969-04-12. Polymyalgia rheumatica.. https://doi.org/10.1136/bmj.2.5649.99
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Sedimentation of hardened erythrocytes in a centrifugal field was studied by time recording of the current chamber in the longitudinal and the transversal directions relative to the cells' movement. The results clearly indicate the existence of an erythrocyte concentration profile during centrifugation. The rates of both longitudinal and transversal current alteration increase with centripetal acceleration and with falling cell concentration. The pellet formed from hardened cells represents virtually incompressible body. It is shown that erythrocyte shape affects the pellet conductivity. Analysis of the data using the modified Stokes' law enables calculation of the cell size distribution. The modal size of macrocytes, normal erythrocytes and two samples of microcytes thus measured was 3.40, 3.01, 2.63 and 2.83 microns, respectively. These data demonstrate that conductometric analysis is useful for investigating abnormalities in erythrocyte size.
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.