Jackson William F
Department of Pharmacology and Toxicology, College of Osteopathic Medicine, Michigan State University, East Lansing, MI, United States.
Front Physiol. 2021 Jul 22;12:699517. doi: 10.3389/fphys.2021.699517. eCollection 2021.
Resistance arteries and downstream arterioles in the peripheral microcirculation contribute substantially to peripheral vascular resistance, control of blood pressure, the distribution of blood flow to and within tissues, capillary pressure, and microvascular fluid exchange. A hall-mark feature of these vessels is myogenic tone. This pressure-induced, steady-state level of vascular smooth muscle activity maintains arteriolar and resistance artery internal diameter at 50-80% of their maximum passive diameter providing these vessels with the ability to dilate, reducing vascular resistance, and increasing blood flow, or constrict to produce the opposite effect. Despite the central importance of resistance artery and arteriolar myogenic tone in cardiovascular physiology and pathophysiology, our understanding of signaling pathways underlying this key microvascular property remains incomplete. This brief review will present our current understanding of the multiple mechanisms that appear to underlie myogenic tone, including the roles played by G-protein-coupled receptors, a variety of ion channels, and several kinases that have been linked to pressure-induced, steady-state activity of vascular smooth muscle cells (VSMCs) in the wall of resistance arteries and arterioles. Emphasis will be placed on the portions of the signaling pathways underlying myogenic tone for which there is lack of consensus in the literature and areas where our understanding is clearly incomplete.
外周微循环中的阻力动脉和下游小动脉对外周血管阻力、血压控制、组织内血流分布、毛细血管压力和微血管液体交换起着重要作用。这些血管的一个标志性特征是肌源性张力。这种由压力诱导的血管平滑肌活动稳态水平使小动脉和阻力动脉的内径维持在其最大被动直径的50%-80%，使这些血管能够扩张，降低血管阻力并增加血流量，或收缩以产生相反的效果。尽管阻力动脉和小动脉肌源性张力在心血管生理和病理生理中至关重要，但我们对这一关键微血管特性的信号通路的理解仍不完整。本简要综述将介绍我们目前对肌源性张力潜在的多种机制的理解，包括G蛋白偶联受体、多种离子通道以及与阻力动脉和小动脉壁中血管平滑肌细胞（VSMC）的压力诱导稳态活动相关的几种激酶所起的作用。重点将放在肌源性张力信号通路中在文献中缺乏共识的部分以及我们理解明显不完整的领域。
