Precapillary servo control of blood pressure and postcapillary adjustment of flow to tissue metabolic status - A new paradigm for local perfusion regulation
Precapillary servo control of blood pressure and postcapillary adjustment of flow to tissue metabolic status - A new paradigm for local perfusion regulation
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DOI：
10.1161/01.cir.94.8.1876
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发表时间：
1996-10-15
期刊：
影响因子：
37.8
通讯作者：
Groebe, K
中科院分区：
文献类型：
--
作者：
Groebe, K
背景目前对微血管系统如何维持组织内环境稳定的认识存在一些不足。目前尚未解决的问题包括（1）毛细血管灌注和静水压力调节的潜在冲突需求的整合，（2）用于将关于组织能量状态的信息从供应不足的组织部位传递到小动脉的信号传输途径的理解，（3）解释实验观察到的毛细血管前和毛细血管后阻力之间的相互关系，和（4）解释如何精确的局部调整灌注代谢demands.Methods和结果一个新的概念，如何局部微血管控制机制协调提出，根据血流量的组织的代谢需要进行调整的小静脉。小动脉的作用仅仅是通过生肌反应和剪切应力诱导的血管舒张来控制毛细血管压力。这一理论的数学模型的介绍和评价使用完善的实验数据从文献中的微血管直径的调节机制排他。模型结果表明，所建议的微血管操作模式在体内存在的条件下是功能性的和有效的。此外，预测的血管反应是足够大，以涵盖整个范围内观察到的运动骨骼肌在调整灌注到更高的性能level.Conclusions毛细血管前压力调节结合毛细血管后调整灌注组织代谢状态是适合于解决上述缺点，在我们目前的理解微血管控制。基于实验数据的数学建模，这种微血管操作模式被证明是功能性的，有效地控制肌肉微循环。
Background There are several shortcomings in current understanding of how the microvasculature maintains tissue homeostasis. Presently unresolved issues include (1) integration of the potentially conflicting needs for capillary perfusion and hydrostatic pressure regulation, (2) an understanding of signal transmission pathways for conveying information about tissue energetic status from undersupplied tissue sites to the arterioles, (3) accounting for the experimentally observed interrelations between precapillary and postcapillary resistances, and (4) an explanation of how precise local adjustment of perfusion to metabolic demands is achieved.Methods and Results A novel conceptualization of how local microvascular control mechanisms are coordinated is proposed, according to which blood flow is adjusted to the metabolic needs of the tissue by the venules. Arteriolar action is merely called on for controlling capillary pressure through myogenic response and shear stress-induced vasodilation. A mathematical model of this theory is introduced and evaluated using well-established experimental data from the literature on regulating mechanisms of microvessel diameters exclusively. The model results demonstrate the suggested mode of microvascular operation to be functional and efficient under conditions present in vivo. Moreover, the predicted vascular responses are large enough to cover the entire range observed in exercising skeletal muscle during adjustment of perfusion to higher performance levels.Conclusions Precapillary pressure regulation combined with postcapillary adjustment of perfusion to tissue metabolic status is suitable to resolve the above shortcomings in our current understanding of microvascular control. With mathematical modeling based on experimental data, this mode of microvascular operation is shown to be functional and effective in controlling muscle microcirculation.