Medical Pharmacology and Physiology, University of Missouri, Columbia, Missouri 65212, USA.
Microcirculation. 2013 Apr;20(3):217-38. doi: 10.1111/micc.12035.
The control of vascular resistance and tissue perfusion reflect coordinated changes in the diameter of feed arteries and the arteriolar networks they supply. Against a background of myogenic tone and metabolic demand, vasoactive signals originating from perivascular sympathetic and sensory nerves are integrated with endothelium-derived signals to produce vasodilation or vasoconstriction. PVNs release adrenergic, cholinergic, peptidergic, purinergic, and nitrergic neurotransmitters that lead to SMC contraction or relaxation via their actions on SMCs, ECs, or other PVNs. ECs release autacoids that can have opposing actions on SMCs. Respective cell layers are connected directly to each other through GJs at discrete sites via MEJs projecting through holes in the IEL. Whereas studies of intercellular communication in the vascular wall have centered on endothelium-derived signals that govern SMC relaxation, attention has increasingly focused on signaling from SMCs to ECs. Thus, via MEJs, neurotransmission from PVNs can evoke distinct responses from ECs subsequent to acting on SMCs. To integrate this emerging area of investigation in light of vasomotor control, the present review synthesizes current understanding of signaling events that originate within SMCs in response to perivascular neurotransmission in light of EC feedback. Although often ignored in studies of the resistance vasculature, PVNs are integral to blood flow control and can provide a physiological stimulus for myoendothelial communication. Greater understanding of these underlying signaling events and how they may be affected by aging and disease will provide new approaches for selective therapeutic interventions.
血管阻力和组织灌注的控制反映了供血动脉和其供应的小动脉网络直径的协调变化。在肌源性张力和代谢需求的背景下，源自血管周围交感神经和感觉神经的血管活性信号与内皮衍生信号整合，产生血管舒张或血管收缩。PVN 释放肾上腺素能、胆碱能、肽能、嘌呤能和一氧化氮能神经递质，通过作用于 SMC、EC 或其他 PVN 来导致 SMC 收缩或松弛。EC 释放自体活性物质，对 SMC 可产生相反的作用。各自的细胞层通过 GJ 在离散部位直接相互连接，通过穿过 IEL 中的孔投射的 MEJ。虽然血管壁细胞间通讯的研究集中在调节 SMC 松弛的内皮衍生信号上，但越来越多的注意力集中在 SMC 向 EC 的信号传递上。因此，通过 MEJ，PVN 的神经传递可以在作用于 SMC 后从 EC 引发独特的反应。为了根据血管舒缩控制整合这一新兴研究领域，本综述综合了目前对血管平滑肌细胞内信号事件的理解，这些信号事件是对血管周围神经传递的反应，同时考虑到 EC 的反馈。尽管在阻力血管的研究中经常被忽视，但 PVN 是血流控制的重要组成部分，并且可以为肌内皮通讯提供生理刺激。对这些潜在信号事件的更多了解，以及它们如何受到衰老和疾病的影响，将为选择性治疗干预提供新的方法。
