Koller Akos, Toth Peter
Department of Pathophysiology and Gerontology, Medical School, University of Pécs, Pécs, Hungary.
J Vasc Res. 2012;49(5):375-89. doi: 10.1159/000338747. Epub 2012 Jun 22.
Regulation of cerebral blood flow (CBF) is the result of multilevel mechanisms to maintain the appropriate blood supply to the brain while having to comply with the limited space available in the cranium. The latter requirement is ensured by the autoregulation of CBF, in which the pressure-sensitive myogenic response is known to play a pivotal role. However, in vivo increases in pressure are accompanied by increases in flow; yet the effects of flow on the vasomotor tone of cerebral vessels are less known. Earlier studies showed flow-sensitive dilation and/or constriction or both, but no clear picture emerged. Recently, the important role of flow-sensitive mechanism(s) eliciting the constriction of cerebral vessels has been demonstrated. This review focuses on the effect of hemodynamic forces (especially intraluminal flow) on the vasomotor tone of cerebral vessels and the underlying cellular and molecular mechanisms. A novel concept of autoregulation of CBF is proposed, suggesting that (in certain areas of the cerebrovascular tree) pressure- and flow-induced constrictions together maintain an effective autoregulation, and that alterations in these mechanisms may contribute to the development of cerebrovascular disorders. Future studies are warranted to explore the signals, the details of signaling processes and the in vivo importance of these mechanisms.
脑血流量（CBF）的调节是多级机制的结果，目的是在必须适应颅骨内有限空间的情况下，维持对大脑的适当血液供应。CBF的自动调节确保了后一项要求，其中已知压力敏感的肌源性反应起着关键作用。然而，体内压力升高伴随着血流量增加；然而，血流对脑血管血管舒缩张力的影响却鲜为人知。早期研究显示了血流敏感的扩张和/或收缩或两者皆有，但并未形成清晰的图景。最近，已证明血流敏感机制在引发脑血管收缩方面的重要作用。本综述重点关注血流动力学力（尤其是管腔内血流）对脑血管血管舒缩张力的影响以及潜在的细胞和分子机制。提出了一种新的CBF自动调节概念，表明（在脑血管树的某些区域）压力和血流诱导的收缩共同维持有效的自动调节，并且这些机制的改变可能导致脑血管疾病的发生。有必要进行进一步研究以探索这些机制的信号、信号传导过程的细节及其在体内的重要性。
