Department of Biomedical Engineering, Amirkabir University of Technology (Tehran Polytechnic), Tehran, Iran.
Research Center of Montreal Heart Institute, Montréal, QC, Canada.
Sci Rep. 2020 Aug 7;10(1):13358. doi: 10.1038/s41598-020-70413-3.
We exploited two-photon microscopy and Doppler optical coherence tomography to examine the cerebral blood flow and tissue pO response to forced treadmill exercise in awake mice. To our knowledge, this is the first study performing both direct measure of brain tissue pO during acute forced exercise and underlying microvascular response at capillary and non-capillary levels. We observed that cerebral perfusion and oxygenation are enhanced during running at 5 m/min compared to rest. At faster running speeds (10 and 15 m/min), decreasing trends in arteriolar and capillary flow speed were observed, which could be due to cerebral autoregulation and constriction of arterioles in response to blood pressure increase. However, tissue pO was maintained, likely due to an increase in RBC linear density. Higher cerebral oxygenation at exercise levels 5-15 m/min suggests beneficial effects of exercise in situations where oxygen delivery to the brain is compromised, such as in aging, atherosclerosis and Alzheimer Disease.
我们利用双光子显微镜和多普勒光相干断层扫描技术来研究清醒小鼠在强制跑步机运动时的大脑血流和组织氧反应。据我们所知，这是首次在急性强制运动期间直接测量脑组织氧，并在毛细血管和非毛细血管水平研究其潜在的微血管反应的研究。我们观察到，与休息相比，在以 5 m/min 的速度跑步时，大脑灌注和氧合增强。在更快的跑步速度（10 和 15 m/min）下，观察到动静脉和毛细血管血流速度呈下降趋势，这可能是由于大脑自动调节和动脉对血压升高的收缩。然而，组织氧分压保持不变，可能是由于红细胞线性密度增加所致。在 5-15 m/min 的运动水平下，大脑氧合作用更高，这表明在大脑供氧受损的情况下，如在衰老、动脉粥样硬化和阿尔茨海默病等情况下，运动具有有益的影响。
