A new view of Starling's hypothesis at the microstructural level
A new view of Starling's hypothesis at the microstructural level
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DOI：
10.1006/mvre.1999.2177
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发表时间：
1999-11-01
影响因子：
3.1
通讯作者：
Weinbaum, S
中科院分区：
文献类型：
--
作者：
Hu, XP;Weinbaum, S
在本文中，我们定量研究了 Michel (Exp. Physiol. 82, 1-30, 1997) 和 Weinbaum (Ann. Biomed. Eng. 26, 1-17, 1998) 提出的假设，即 Starling 力是由内皮表面糖萼上的静水压和胶体渗透压的局部差异决定的，我们认为内皮表面糖萼是血浆蛋白的主要分子筛，而不是与血浆和组织之间毛细血管壁上的静水压力和胶体渗透压的整体差异相比，正如迄今为止普遍假设的那样。开发了一种空间异质微观结构模型，以在细胞水平上解释为什么在 Michel 和 Phillips (J. Physiol. 388, 421-435, 1987) 对青蛙肠系膜毛细血管进行的短暂瞬态实验中，在低毛细血管压力下会出现胶体渗透吸收，但一旦达到稳定状态，就会出现小的正滤过。新模型还预测，表面糖萼后面的局部蛋白质浓度可能与组织蛋白质浓度有很大差异，因为当孔口处的局部佩克莱特数 > 1 时，蛋白质通过连接链中的孔状孔的对流通量将极大地阻碍蛋白质向后扩散到裂口的腔侧。最终结果是毛细血管中的过滤远低于迄今为止实现的水平，并且可能不需要静脉重吸收。 (C) 1999 年学术出版社。
In this paper we quantitatively investigate the hypothesis proposed by Michel (Exp. Physiol. 82, 1-30, 1997) and Weinbaum (Ann. Biomed. Eng. 26, 1-17, 1998) that the Starling forces are determined by the local difference in the hydrostatic and colloid osmotic pressure across the endothelial surface glycocalyx, which we propose is the primary molecular sieve for plasma proteins, rather than the global difference in the hydrostatic and oncotic pressure across the capillary wall between the plasma and tissue, as has been universally assumed until now. A spatially heterogeneous microstructural model is developed to explain at the cellular level why there is oncotic absorption at low capillary pressures in the short-lived transient experiments of Michel and Phillips (J. Physiol. 388, 421-435, 1987) on frog mesentery capillary, but a small positive filtration once a steady state is achieved. The new model also predicts that the local protein concentration behind the surface glycocalyx can differ greatly from the tissue protein concentration, since the convective flux of proteins through the orifice-like pores in the junction strand will greatly impede the back diffusion of the proteins into the lumen side of the cleft when the local Peclet number at the orifice is >1. The net result is that the filtration in the capillaries is far less than heretofore realized and there may be no need for venous reabsorption. (C) 1999 Academic Press.