Process of cell‐free layer formation after arteriolar bifurcation and its physiological effects

Abstract

Understanding the formation of cell‐free layer (CFL) in arteriolar networks has been of great interest, particularly for its significance in regulation of blood flow. The heterogeneous distribution of red blood cells (RBCs) modulated by the formation of CFL in arteriolar bifurcations potentially leads to alterations in tissue oxygenation (O2) and vascular tone due to varying nitric oxide (NO) production in the endothelium. Accordingly, we investigated the formation of CFL from 2 to 6 vessel‐diameter (2D–6D) downstream of arteriolar bifurcations in the rat cremaster muscle under reduced flow conditions (pseudoshear rates = 15.6 ± 2.0 s−1). We accounted for the spatiotemporal variations in the wall shear stress, velocity profile and core hematocrit along the downstream vessels by extending our previous image‐based two‐dimensional transient model, which was unprecedented in previous computational models. Our experimental results showed that an asymmetric formation of CFL width along the vessel walls was evident up to 6D from the bifurcating point. The recovery of CFL symmetry appeared to be impeded by RBC aggregation. Our numerical prediction of soluble guanylate cyclase (sGC) activity revealed that vasoactivity might not occur uniformly within an inter‐bifurcation distance, in particular under reduced flow and aggregating conditions.Support or Funding InformationNUS FRC