Starling forces that oppose filtration after tissue oncotic pressure is increased
Starling forces that oppose filtration after tissue oncotic pressure is increased
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DOI：
10.1152/ajpheart.2000.279.4.h1724
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发表时间：
2000-10-01
影响因子：
4.8
通讯作者：
Weinbaum, S
中科院分区：
文献类型：
--
作者：
Hu, X;Adamson, RH;Weinbaum, S
我们测试了这样一个假设，即反对液体通过微血管壁的有效肿瘤力是跨越内皮细胞表面糖萼的局部肿瘤性压力差，而不是血浆和组织之间的整体差异。在单个蛙肠系膜微血管中灌流和灌流含有50 mg/ml白蛋白的溶液，施加在微血管壁上的有效肿瘤性压力与单独灌流液中白蛋白为50 mg/ml时的测量结果没有显著差异。在毛细血管压力为10到35 cmH(2)O的瞬时和稳态过滤过程中进行了测量。内皮间隙中水和溶质耦合流动的细胞水平模型显示，水通量通过连接链上的小断裂和白蛋白有限的反向扩散进入甘氨酸乙酯组织侧的保护空间。因此，反对过滤的肿瘤力大于根据血液到组织蛋白质浓度差异估计的力，而跨毛细血管液体流量小于根据全球肿瘤性和静水压力差异估计的流量。
We tested the hypothesis that the effective oncotic force that opposes fluid filtration across the microvessel wall is the local oncotic pressure difference across the endothelial surface glycocalyx and not the global difference between the plasma and tissue. In single frog mesenteric microvessels perfused and superfused with solutions containing 50 mg/ml albumin, the effective oncotic pressure exerted across the microvessel wall was not significantly different from that measured when the perfusate alone contained albumin at 50 mg/ml. Measurements were made during transient and steady-state filtration at capillary pressures between 10 and 35 cmH(2)O. A cellular-level model of coupled water and solute flows in the interendothelial cleft showed water flux through small breaks in the junctional strand limited back diffusion of albumin into the protected space on the tissue side of the glycocalyx. Thus oncotic forces opposing filtration are larger than those estimated from blood-to-tissue protein concentration differences, and transcapillary fluid flux is smaller than estimated from global differences in oncotic and hydrostatic pressures.