Erythrocyte aggregation may promote uneven spatial distribution of NO/O₂ in the downstream vessel of arteriolar bifurcations

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• 作者：Yan Cheng Ng^a ; ^b ; ¹ ; Bumseok Namgung^b ; ¹ ; Hwa Liang Leo^a ; ^b ; Sangho Kim^a ; ^b ; ^c ; ^{bieks@nus.edu.sg" class="auth_mail" title="E-mail the corresponding author}
• 关键词：BL ; blood lumen ; CFL ; cell-free layer ; DNO ; c ; diffusivity of NO in compartment c ; DO2DO2 ; c ; diffusivity of O2 in compartment c ; EC ; endothelial cell ; Hsys ; systemic hematocrit ; Hc ; core hematocrit ; D ; internal diameter of vessel ; KM ; Michealis&ndash ; Menten constant in EC ; NO ; nitric Oxide ; RBC ; red blood cell ; RNO ; EC/ref ; reference NO production rate in EC ; SM ; smooth muscle layer ; O2 ; Oxygen ; PO2PO2 ; c ; partial pressure of O2 in compartment c ; Vc ; centerline velocity of blood flow ; Vmean ; mean v
• 刊名：Journal of Biomechanics
• 出版年：2016
• 出版时间：26 July 2016
• 年：2016
• 卷：49
• 期：11
• 页码：2241-2248
• 全文大小：940 K

文摘

This study examined the effect of red blood cell (RBC) aggregation on nitric oxide (NO) and oxygen (O₂) distributions in the downstream vessels of arteriolar bifurcations. Particular attention was paid to the inherent formation of asymmetric cell-free layer (CFL) widths in the downstream vessels and its consequential impact on the NO/O₂ bioavailability after the bifurcations. A microscopic image-based two-dimensional transient model was used to predict the NO/O₂ distribution by utilizing the in vivo CFL width data obtained under non-, normal- and hyper-aggregating conditions at the pseudoshear rate of 15.6±2.0 s⁻¹. In vivo experimental result showed that the asymmetry of CFL widths was enhanced by the elevation in RBC aggregation level. The model demonstrated that NO bioavailability was regulated by the dynamic fluctuation of the local CFL widths, which is corollary to its modulation of wall shear stress. Accordingly, the uneven distribution of NO/O₂ was prominent at opposite sides of the arterioles up to six vessel-diameter (6D) away from the bifurcating point, and this was further enhanced by increasing the levels of RBC aggregation. Our findings suggested that RBC aggregation potentially augments both the formation of asymmetric CFL widths and its influence on the uneven distribution of NO/O₂ in the downstream flow of an arteriolar bifurcation. The extended heterogeneity of NO/O₂ downstream (2D–6D) also implied its potential propagation throughout the entire arteriolar microvasculature.