Klitzman B, Johnson P C
Am J Physiol. 1982 Feb;242(2):H211-9. doi: 10.1152/ajpheart.1982.242.2.H211.
Vascular geometry and red cell distribution were examined in 133 capillaries by means of intravital microscopy in the cremaster muscle of the pentobarbital-anesthetized hamster. Significant correlations (P less than 0.01) were found between diameter and flow, length and resistance, red cell transit time and flow, and red cell flux and hematocrit. Most unexpected was the lack of correlation (P greater than 0.2) between flow and resistance, length, or hematocrit. In addition, we analyzed the relation between blood flow and red cell flux at capillary bifurcations. The red blood cells had a slight (7%), but significant (P less than 0.025), tendency to enter the branch having either higher flow, red cell velocity, or pseudoshear rate (velocity/diameter). The net effect of the preferential red cell flow was to reduce mean capillary hematocrit from 13.7% prior to the bifurcation to 13.3% in the two branches. Finally, increasing the oxygen level of the superfusate above the muscle caused vasoconstriction and an increased heterogeneity of capillary red cell flux and hematocrit, decreasing the capacity for oxygen transport to the tissue.
通过活体显微镜检查，在戊巴比妥麻醉的仓鼠提睾肌中的133根毛细血管中研究了血管几何形状和红细胞分布。发现直径与流量、长度与阻力、红细胞通过时间与流量以及红细胞通量与血细胞比容之间存在显著相关性（P小于0.01）。最出乎意料的是流量与阻力、长度或血细胞比容之间缺乏相关性（P大于0.2）。此外，我们分析了毛细血管分叉处血流与红细胞通量之间的关系。红细胞有轻微（7%）但显著（P小于0.025）的倾向进入具有较高流量、红细胞速度或假剪切率（速度/直径）的分支。红细胞优先流动的净效应是使分叉前的平均毛细血管血细胞比容从13.7%降至两个分支中的13.3%。最后，将肌肉上方灌注液的氧水平提高会导致血管收缩，毛细血管红细胞通量和血细胞比容的异质性增加，从而降低向组织输送氧气的能力。
