Determination of microvascular flow pattern formation in vivo
Determination of microvascular flow pattern formation in vivo
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DOI：
10.1152/ajpheart.2000.278.4.h1142
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发表时间：
2000-04-01
影响因子：
4.8
通讯作者：
Pries, AR
中科院分区：
文献类型：
--
作者：
Osterloh, K;Gaehtgens, P;Pries, AR
微血管中的血流与体外长直玻璃管中红细胞（RBC）的血流明显不同。体内情况的特征在于存在有利于聚集的血浆、血管节段的不规则几何形状和频繁的分支点。在这里，提出了一种方法来表征在活体显微镜的基础上记录的光强度图案的傅立叶分析的微血管血流的流动模式。所得到的功率谱的图案尺寸分布方面的解释进行了验证，采用人工纹理的模型实验和理想化的光谱的逆变换。测定的微血管中RBC流动模式的大小范围从毛细血管中的8 μ m到>30 μ m的血管中的14 μ m。随着剪切速率的增加，在100 s（-1）以上，图案尺寸增加，可能反映了短寿命的流动集群的形成。低于100 s（-1）时，在使用局部封闭和高分子量葡聚糖处理的实验中发现，随着剪切速率的降低，图案尺寸增加，这表明形成了聚集体。红细胞流动模式的产生和破坏的动态过程可以很好地促进在体外周血管床中的流动阻力。
Blood flow in microvessels differs significantly from that of red blood cells (RBC) flowing through long, straight glass tubes in vitro. The in vivo situation is characterized by the presence of plasma favoring aggregation, by the irregular geometry of vessel segments, and by frequent branching points. Here, a method is presented to characterize flow patterns in microvascular blood flow during intravital microscopy based on Fourier analysis of recorded light intensity patterns. The interpretation of the resulting power spectra in terms of pattern size distribution was validated by model experiments employing artificial textures and by reverse transformation of idealized spectra. The determined size of RBC flow patterns in microvessels ranged from similar to 8 mu m in capillaries to similar to 14 mu m in vessels of >30 mu m. With increasing shear rate above similar to 100 s(-1) pattern size increased, possibly reflecting formation of short-lived flow clusters. Below similar to 100 s(-1) an increase of pattern size with decreasing shear rate was found in experiments using local occlusion and treatment with high-molecular-weight dextran, suggesting the formation of aggregates. The dynamic process of generation and destruction of RBC flow patterns could well contribute to flow resistance in vivo in peripheral vascular beds.