Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, Illinois, USA.
Department of Electrical Engineering, Polytechnique Montréal, Montreal, Canada.
Microcirculation. 2024 Apr;31(3):e12845. doi: 10.1111/micc.12845. Epub 2024 Jan 24.
The role of cerebral microvasculature in cognitive dysfunction can be investigated by identifying the impact of blood flow on cortical tissue oxygenation. In this paper, the impact of capillary stalls on microcirculatory characteristics such as flow and hematocrit (Ht) in the cortical angioarchitecture is studied.
Using a deterministic mathematical model to simulate blood flow in a realistic mouse cortex, hemodynamics parameters, including pressure, flow, vessel diameter-adjustable hematocrit, and transit time are calculated as a function of stalling events.
Using a non-linear plasma skimming model, it is observed that Ht increases in the penetrating arteries from the pial vessels as a function of cortical depth. The incidence of stalling on Ht distribution along the blood network vessels shows reduction of RBCs around the tissue near occlusion sites and decreased Ht concentration downstream from the blockage points. Moreover, upstream of the occlusion, there is a noticeable increase of the Ht, leading to larger flow resistance due to higher blood viscosity. We predicted marked changes in transit time behavior due to stalls which match trends observed in mice in vivo.
These changes to blood cell quantity and quality may be implicated in the development of Alzheimer's disease and contribute to the course of the illness.
通过研究血流对皮质组织氧合的影响，可以研究脑微血管在认知功能障碍中的作用。本文研究了毛细血管停滞对皮质血管结构中血流和血细胞比容（Ht）等微循环特征的影响。
使用确定性数学模型模拟真实小鼠皮质中的血流，计算包括压力、流量、可调节血管直径的血细胞比容和通过时间在内的血液动力学参数，作为停滞事件的函数。
使用非线性血浆撇除模型，观察到 Ht 从脑膜血管中的穿透动脉随着皮质深度的增加而增加。停滞对沿血管网络分布的 Ht 的影响表明，在阻塞部位附近的组织周围 RBC 减少，并且在阻塞点下游的 Ht 浓度降低。此外，在阻塞物的上游，Ht 明显增加，由于血液粘度增加，导致更大的流动阻力。我们预测由于停滞会导致明显的通过时间行为变化，这与体内观察到的老鼠趋势相匹配。
这些血细胞数量和质量的变化可能与阿尔茨海默病的发展有关，并导致疾病的进程。
