Structural Adaptation of Microvascular Networks and Development of Hypertension
Structural Adaptation of Microvascular Networks and Development of Hypertension
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DOI：
10.1038/sj.mn.7800144
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发表时间：
2002-08
期刊：
影响因子：
2.4
通讯作者：
A. Pries;T. Secomb
中科院分区：
文献类型：
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作者：
A. Pries;T. Secomb
血管具有动态结构适应能力，其直径和壁厚会随着血流动力学条件的慢性变化而变化。这种结构变化会对血管血流阻力产生很大影响。对血流动力学应力的结构响应，即血流引起的壁剪切应力和跨壁压力引起的周壁张力，已被广泛记录。一般来说，剪切应力的增加会导致血管直径的增加，而跨壁压力的增加会产生相反的效果。已经开发出理论模型来分析当系统循环条件发生变化时这些反应对微血管网络行为的影响。假设心输出量的初始增加会同时增加流量和驱动压力。根据模型，随着流量的增加，结构调整导致整体网络流动阻力大幅增加，从而放大了最初施加的驱动压力的增加。这种行为是由于各个血管段对血管内压力的适应而产生的，与高血压发展的数据一致，这表明心输出量的增加先于外周阻力的增加，而外周阻力的增加是已确定的高血压的特征。因此，血管对周壁应力的敏感性可能在高血压的发生中起着至关重要的作用。Microcirculation(2002)9,305–314。号码：10.1038/sj.mn.7800144
Blood vessels are capable of dynamic structural adaptation in which their diameters and wall thicknesses change in response to chronic changes in hemodynamic conditions. Such structural changes can have large effects on vascular resistance to blood flow. Structural responses to hemodynamic stresses, i.e., wall shear stress resulting from blood flow and circumferential wall tension resulting from transmural pressure, have been extensively documented. Generally, increased shear stress causes increases in vessel diameter, whereas increased transmural pressure causes opposite effects. Theoretical models have been developed to analyze the consequences of these responses for the behavior of microvascular networks when subjected to changes in systemic circulatory conditions. An initial increase of cardiac output is assumed to increase flow and driving pressure in parallel. According to the models, structural adaptation results in substantially increased overall network flow resistance as flow is increased, and thus amplification of the initially imposed increase in driving pressure. This behavior, resulting from adaptation of individual vessel segments to intravascular pressure, is consistent with data on the development of hypertension, which suggest that an increase in cardiac output precedes the increase in peripheral resistance that is characteristic of established hypertension. Thus, vascular sensitivity to circumferential wall stress may play a crucial role in the development of hypertension.Microcirculation(2002)9,305–314. doi: 10.1038/sj.mn.7800144