College of Information Engineering, Zhejiang University of Technology, 310023 Hangzhou, China.
Department of Biomedical Engineering, Key Laboratory of Biomedical Engineering of MOE, Zhejiang University, 310027 Hangzhou, China.
Microvasc Res. 2022 Jan;139:104259. doi: 10.1016/j.mvr.2021.104259. Epub 2021 Oct 6.
Blood flow pulsatility is an important determinant of macro- and microvascular physiology. Pulsatility is damped largely in the microcirculation, but the characteristics of this damping and the factors that regulate it have not been fully elucidated yet. Applying computational approaches to real microvascular network geometry, we examined the pattern of pulsatility damping and the role of potential damping factors, including pulse frequency, vascular viscous resistance, vascular compliance, viscoelastic behavior of the vessel wall, and wave propagation and reflection. To this end, three full rat mesenteric vascular networks were reconstructed from intravital microscopic recordings, a one-dimensional (1D) model was used to reproduce pulsatile properties within the network, and potential damping factors were examined by sensitivity analysis. Results demonstrate that blood flow pulsatility is predominantly damped at the arteriolar side and remains at a low level at the venular side. Damping was sensitive to pulse frequency, vascular viscous resistance and vascular compliance, whereas viscoelasticity of the vessel wall or wave propagation and reflection contributed little to pulsatility damping. The present results contribute to our understanding of mechanical forces and their regulation in the microcirculation.
血流搏动性是宏观和微观血管生理学的一个重要决定因素。搏动性在微循环中被大大减弱，但这种阻尼的特征以及调节它的因素尚未被充分阐明。我们应用计算方法研究了真实微血管网络几何形状中的搏动性阻尼模式以及潜在的阻尼因素的作用，包括脉冲频率、血管粘性阻力、血管顺应性、血管壁的粘弹性行为以及波的传播和反射。为此，从活体显微镜记录中重建了三个完整的大鼠肠系膜血管网络，使用一维（1D）模型在网络内再现脉动特性，并通过敏感性分析检查潜在的阻尼因素。结果表明，血流搏动性主要在小动脉侧被阻尼，并在小静脉侧保持在低水平。阻尼对脉冲频率、血管粘性阻力和血管顺应性敏感，而血管壁的粘弹性或波的传播和反射对搏动性阻尼的贡献很小。本研究结果有助于我们理解微循环中的机械力及其调节。
