Red blood cell lingering modulates hematocrit distribution in the microcirculation

Area of Science:

• Physiology
• Biophysics
• Microcirculation

Background:

• Red blood cell (RBC) distribution in microcirculation is crucial for oxygen and solute transport.
• RBCs typically partition disproportionately to blood flow at bifurcations, causing hematocrit heterogeneity.
• Recent studies show deviations from established RBC partitioning laws.

Purpose of the Study:

• To quantify the influence of RBC lingering on RBC partitioning at microvascular bifurcations.
• To investigate the correlation between cell lingering and deviations from established phase-separation laws.
• To explore the impact of bifurcation geometry and RBC rigidity on lingering behavior.

Main Methods:

• Combined in vivo experiments and in silico simulations.
• Developed a method to quantify RBC lingering at capillary-level bifurcations.
• Analyzed RBC partitioning deviations from empirical predictions.

Main Results:

• RBC lingering at bifurcation apices was quantified.
• Cell lingering correlates with deviations from established RBC phase-separation laws.
• Bifurcation geometry and RBC membrane rigidity influence lingering; rigid cells linger less.

Conclusions:

• RBC lingering is a significant mechanism affecting RBC partitioning in microcirculation.
• Understanding RBC lingering is vital for studying diseases involving abnormal RBC rigidity (e.g., malaria, sickle-cell disease).
• RBC lingering impacts microcirculatory blood flow and vascular network alterations in pathological conditions.