Faber James E
Department of Cell Biology and Physiology, Curriculum in Neuroscience, McAllister Heart Institute, University of North Carolina, Chapel Hill, NC, USA.
J Cereb Blood Flow Metab. 2025 Mar 12:271678X251322378. doi: 10.1177/0271678X251322378.
Collateral blood vessels are unique, naturally occurring endogenous bypass vessels that provide alternative pathways for oxygen delivery in obstructive arterial conditions and diseases. Surprisingly however, the capacity of the collateral circulation to provide protection varies greatly among individuals, resulting in a significant fraction having poor collateral circulation in their tissues. We recently reviewed evidence that the presence of naturally-occurring polymorphisms in genes that determine the number and diameter of collaterals that form during development (ie, genetic background), is a major contributor to this variation. The purpose of this review is to summarize current understanding of the other determinants of collateral blood flow, drawing on both animal and human studies. These include the level of smooth muscle tone in collaterals, hemodynamic forces, how collaterals form during development (collaterogenesis), formation of additional new collaterals during adulthood, loss of collaterals with aging and cardiovascular risk factor presence (rarefaction), and collateral remodeling (structural lumen enlargement). We also review emerging evidence that collaterals not only provide protection in ischemic conditions but may also serve a physiological function in healthy individuals. Primary focus is on studies conducted in brain, however relevant findings in other tissues are also reviewed, as are questions for future investigation.
侧支血管是独特的、自然存在的内源性旁路血管，在阻塞性动脉疾病中为氧气输送提供替代途径。然而，令人惊讶的是，侧支循环提供保护的能力在个体之间差异很大，导致很大一部分人的组织侧支循环较差。我们最近回顾了证据，发现决定发育过程中形成的侧支数量和直径的基因（即遗传背景）中自然存在的多态性是造成这种差异的主要因素。本综述的目的是利用动物和人体研究，总结目前对侧支血流其他决定因素的认识。这些因素包括侧支血管平滑肌张力水平、血流动力学力量、发育过程中侧支血管的形成方式（侧支血管生成）、成年期额外新侧支血管的形成、衰老和存在心血管危险因素时侧支血管的丧失（侧支血管稀疏）以及侧支血管重塑（管腔结构扩大）。我们还回顾了新出现的证据，即侧支血管不仅在缺血状态下提供保护，而且在健康个体中可能也具有生理功能。主要关注在大脑中进行的研究，不过也会回顾其他组织中的相关发现以及未来研究的问题。
