Hindered transport of macromolecules through a single row of cylinders: application to glomerular filtration.
Hindered transport of macromolecules through a single row of cylinders: application to glomerular filtration.
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阻碍大分子通过单排圆柱体的运输：应用于肾小球滤过。
DOI：
10.1115/1.2794202
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发表时间：
1995
期刊：
影响因子：
--
通讯作者：
Deen,WM
中科院分区：
文献类型：
--
作者：
Drumond,MC;Deen,WM
肾小球毛细血管的狭缝隔膜形成超滤屏障，其可以近似为一排大分子尺寸的圆柱形纤维。为了描述血浆蛋白质和其他大分子通过这个屏障的受阻运输，我们开发了一个近似的流体动力学模型，用于球形布朗粒子通过一排无限长的圆柱体。通过计算Pe ≤ 1的宽范围分子尺寸的浓度分布来评估狭缝光阑的选择性，其中Pe是基于圆柱体半径的佩克莱数。狭缝光阑的筛分系数计算为θSD= CB/CO，其中CO为圆柱体上游指定距离处的平均浓度（对应于基底膜的位置），CB为远下游的浓度（对应于Bowman空间）。先前使用大鼠进行的实验性筛分研究的结果可以通过假定狭缝隔膜纤维之间的间距分布较宽来近似解释。将θ SD的结果与肾小球基底膜模型的计算结果进行比较，表明狭缝隔膜是整个屏障中尺寸限制更大的部分。
The slit diaphragms of renal glomerular capillaries form an ultrafiltration barrier which may be approximated as a row of cylindrical fibers of macromolecular dimensions. To describe the hindered transport of plasma proteins and other macromolecules through this barrier, we developed an approximate hydrodynamic model for spherical, Brownian particles passing through a row of infinitely long cylinders. The selectivity of the slit diaphragm was assessed by computing concentration profiles for a wide range of molecular sizes for Pe ≤ 1, where Pe is a Peclet number based on the cylinder radius. The sieving coefficient for the slit diaphragm was computed as θSD= CB/CO, where COwas the average concentration at a specified distance upstream from the cylinders (corresponding to the location of the basement membrane), and CBwas the concentration far downstream (corresponding to Bowman’s space). The results of previous experimental sieving studies using rats could be accounted for approximately by postulating a wide distribution of spacings between the fibers of the slit diaphragm. Comparing the results for θSDwith calculations for a model of the glomerular basement membrane suggests that the slit diaphragm is by far the more size-restrictive part of the overall barrier.