Affiliations: [a] Department of Neurology, University of Oregon Health Sciences Center, Portland, Oregon 97201 | [b] Biocolloid Science Research Laboratory, Providence Medical Center, Portland, Oregon 97213
Note: [] Invited by: Editor A. Silberberg
Abstract: Low molecular weight hydroxyethyl starch (HES) was examined for its capacity to aggregate human erythrocytes (RBC) suspended in phosphate buffered saline (PBS). Preliminary studies showed that the effect of RES was dependent not only on the concentration of HES present but on the shear history of the sample as well. After a procedure for standardizing the shear history of the samples was established, measurements of the low shear viscosity, erythrocyte sedimentation rate (ESR) and zeta sedimentation ratio (ZSR) of the RBC-RES suspensions showed that RBC aggregation increased with HES concentration. This trend continued until an HES concentration of ∼ 4% was reached. Further increases in HES concentration reduced the extent of RBC aggregation. Decreases in the extent of aggregation may have arisen from electrostatic repulsive forces which increase monotonically with RES concentration.
