Aggregation behavior and electrophoretic mobility of red blood cells in various mammalian species.

The research article explores how red blood cells (RBC) aggregate, or clump together, in different mammalian species and investigates their electrophoretic mobility (EPM), or the speed at which they move when under the influence of an electric field. The study reveals variations in these aspects among guinea pigs, rabbits, rats, humans, and horses.

Study Methodology

• The study examined how red blood cells aggregate in different species and investigated their EPM. This was done using cells re-suspended in isotonic 500 kDa dextran solutions.
• Aggregation studies were also carried out using the animals’ own plasma, a part of blood that contains proteins.
• The study built upon previous research findings that have reported differences in RBC aggregation in whole blood, RBC in autologous plasma, and washed RBC re-suspended in polymer solutions.

Key Findings

• The research findings suggested that the aggregation of RBC is species-specific, meaning it differs from one species to the next. The level of aggregation in both plasma and dextran, a complex branched glucan (sugar molecule), varied in the following order (from most to least aggregation): horse > human > rat > rabbit > guinea pig.
• Moreover, there was a notable correlation between RBC aggregation in plasma and dextran.
• The investigation of the electrophoretic mobility of RBCs showed similar values for rats, humans, and horses in Phosphate-Buffered Saline (PBS). Guinea pigs had noticeably lower values, and rabbits had significantly reduced EPM.
• These EPM values and their order remained consistent when measured in the dextran solution.
• The study proposed that these relative EPM results indicate the formation of a polymer-poor, low viscosity depletion layer at the surface of the RBC, with this depletion being most significant for horse RBCs.

Interpreting and Applying the Results

• The observed correlations between EPM and aggregation provided insight into the Depletion Model of aggregation. This model explains RBC aggregation as a consequence of a concentrated area of proteins or polymers in the plasma that are excluded from the zone between adjacent RBCs, thus causing the cells to aggregate.
• However, the correlations observed in this study did not fully explain the differences in aggregation between various species. The authors suggest that additional studies are needed to explore these phenomena at various ionic strengths, and with various fractions of dextran, which might help elucidate further details.