SIMULTANEOUS INFLUENCE OF ERYTHROCYTE DEFORMABILITY AND MACROMOLECULES IN THE MEDIUM ON ERYTHROCYTE AGGREGATION - A KINETIC-STUDY BY A LASER SCATTERING TECHNIQUE

The aggregation and sedimentation kinetics of human erythrocytes was s tudied by modifying the cellular properties and medium compositions si multaneously. Dextrans of average molecular weight 70400 and 494000 we re used to provide suspending medium modifications, while diamide (dia zene dicarboxylic acid bis(N,N-dimethylamide)) was used to alter the m embrane structural properties. Laser scattering method was employed fo r this study, and it was compared with a kinetic method combined with a low-shear rheoscope and an image analyzer. From scattered light inte nsity profiles continuously obtained during aggregation of erythrocyte s and sedimentation of the aggregates, characteristic kinetic paramete rs were computed. Kinetic parameters obtained from a phase of the one- dimensional aggregate formation and sedimentation corresponded well to the velocity of rouleaux formation obtained by the low-shear rheoscop e technique. Dextrans accelerated the erythrocyte aggregation and the sedimentation, and diamide treatment suppressed the process by decreas ing the erythrocyte deformability. The aggregating force by dextrans o vercame the disaggregating force by the decreased deformability. Howev er, the arrangement of erythrocytes as expressed in specific units for aggregates (i.e., rouleaux) became irregular by decreasing the erythr ocyte deformability. In conclusion, the progression of erythrocyte agg regation and the structure of the aggregates were dependent on both er ythrocyte properties and macromolecules in the medium.