Huazhong University of Science and Technology, Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Wuhan 430074, China.
J Biomed Opt. 2012 Dec;17(12):125001. doi: 10.1117/1.JBO.17.12.125001.
Cerebral blood flow (CBF) is critical for the maintenance of cerebral function by guaranteed constant oxygen and glucose supply to brain. Collateral channels (CCs) are recruited to provide alternatives to CBF to ischemic regions once the primary vessel is occluded during ischemic stroke. However, the knowledge of the relationship between dynamic evolution of collateral flow and the distribution of regional blood flow remains limited. In this study, laser speckle imaging was used to assess dynamic changes of CCs and regional blood flow in a rat cortex with permanent middle cerebral artery occlusion (MCAo). We found that CCs immediately provided blood flow to ischemic territories after MCAo. More importantly, there were three kinds of dynamic changes of CCs during acute stroke: persistent CC, impermanent CC, and transient CC, respectively, related to different distributions of regional blood flow. Although there was the possible occurrence of peri-infarct depolarization (PID) during ischemia, there was no obvious significance about the onset time and duration of CCs between rats with and without PID. These results suggest that the initial arising of CCs does not ensure their persistence, and that collateral flow could be varied with distribution of regional blood flow in acute ischemic stroke, which may facilitate the understanding of collateral recruitment and promote the development of collateral therapeutics in the future.
脑血流 (CBF) 对于维持大脑功能至关重要，因为它可以保证大脑持续获得充足的氧气和葡萄糖供应。一旦在缺血性脑卒中期间主要血管被阻塞，侧支通道 (CC) 就会被募集以向缺血区域提供替代 CBF 的途径。然而，关于侧支血流的动态演变与区域性血流分布之间的关系的知识仍然有限。在这项研究中，激光散斑成像被用于评估永久性大脑中动脉阻塞 (MCAo) 后大鼠皮质中 CC 和区域性血流的动态变化。我们发现，CC 在 MCAo 后立即向缺血区域提供血流。更重要的是，在急性脑卒中期间，CC 有三种动态变化：持续的 CC、短暂的 CC 和暂时的 CC，分别与不同的区域性血流分布有关。尽管在缺血期间可能会发生周边梗死去极化 (PID)，但在有和没有 PID 的大鼠之间，CC 的起始时间和持续时间没有明显差异。这些结果表明，CC 的初始出现并不能保证其持续存在，并且在急性缺血性脑卒中期间，侧支血流可能会随着区域性血流分布的变化而变化，这可能有助于理解侧支募集，并为未来的侧支治疗方法的发展提供帮助。
