Institute of Biomedical Engineering, École Polytechnique de Montréal, Montréal, QC, Canada.
Research Center, Montreal Heart Institute, Montréal, QC, Canada.
PLoS One. 2019 Aug 30;14(8):e0221547. doi: 10.1371/journal.pone.0221547. eCollection 2019.
Chronic atherosclerosis may cause cerebral hypoperfusion and inadequate brain oxygenation, contributing to the progression of cognitive decline. In this study, we exploited two-photon phosphorescence lifetime microscopy to measure the absolute partial pressure of oxygen (PO2) in cortical tissue in both young and old LDLR-/-, hApoB100+/+ mice, spontaneously developing atherosclerosis with age. Capillary red-blood-cell (RBC) speed, flux, hematocrit and capillary diameter were also measured by two-photon imaging of FITC-labelled blood plasma. Our results show positive correlations between RBC speed, flux, diameter and capillary-adjacent tissue PO2. When compared to the young mice, we observed lower tissue PO2, lower RBC speed and flux, and smaller capillary diameter in the old atherosclerotic mice. The old mice also exhibited a higher spatial heterogeneity of tissue PO2, and RBC speed and flux, suggesting a less efficient oxygen extraction.
慢性动脉粥样硬化可能导致脑灌注不足和脑供氧不足，从而导致认知能力下降的进展。在这项研究中，我们利用双光子磷光寿命显微镜测量了年轻和年老 LDLR-/-, hApoB100+/+ 小鼠（随年龄自然发生动脉粥样硬化）皮质组织中的绝对氧分压 (PO2)。还通过双光子成像测量了 FITC 标记的血浆中的红细胞（RBC）速度、流量、血细胞比容和毛细血管直径。我们的结果表明 RBC 速度、流量、直径与毛细血管相邻组织 PO2 之间存在正相关关系。与年轻小鼠相比，我们在年老的动脉粥样硬化小鼠中观察到更低的组织 PO2、更低的 RBC 速度和流量以及更小的毛细血管直径。年老的小鼠还表现出组织 PO2、RBC 速度和流量的空间异质性更高，这表明氧气提取效率较低。
