Federspiel W J, Sarelius I H
Microvasc Res. 1984 May;27(3):273-85. doi: 10.1016/0026-2862(84)90059-1.
It is generally assumed that capillary blood is homogeneous for O2 supply and that red cells can provide a constant, uniform flux of O2 out of the capillary regardless of the spacing between cells. Using a simplified model of red cells moving through a capillary in skeletal muscle, an approximate analysis is developed to study the effect of red cell spacing on the ability of erythrocytes to provide a constant, uniform flux of O2 at the capillary wall. The results suggest the existence of a critical red cell separation distance above which the flux of O2 at the capillary wall between red cells cannot remain uniform and the capillary blood is no longer homogeneous for O2 supply. In resting muscle the predicted critical separation distance is greater than four cell lengths. During maximal O2 consumption, the critical separation distance predicted by the model is one cell length. These predictions agree closely with in vivo observations of red cell spacing. The total red cell flux through a capillary is determined not only by red cell spacing (hematocrit) but also by erythrocyte velocity; a simple example is given which suggests that changes in each of these variables are not equivalent in maintaining a constant and uniform flux of O2 at the capillary wall.
一般认为，毛细血管血液在氧气供应方面是均匀的，并且红细胞能够从毛细血管中提供恒定、均匀的氧气通量，而与细胞间距无关。使用一个简化的红细胞在骨骼肌毛细血管中流动的模型，进行了近似分析，以研究红细胞间距对红细胞在毛细血管壁提供恒定、均匀氧气通量能力的影响。结果表明存在一个临界红细胞分离距离，超过该距离，红细胞之间毛细血管壁处的氧气通量就无法保持均匀，并且毛细血管血液在氧气供应方面不再均匀。在静息肌肉中，预测的临界分离距离大于四个细胞长度。在最大耗氧量期间，该模型预测的临界分离距离为一个细胞长度。这些预测与红细胞间距的体内观察结果密切相符。通过毛细血管的总红细胞通量不仅取决于红细胞间距（血细胞比容），还取决于红细胞速度；给出了一个简单示例，表明这些变量中的每一个变化在维持毛细血管壁处恒定、均匀的氧气通量方面并不等效。
