Transport by epithelia with compliant lateral intercellular spaces: asymmetric oncotic effects across the rat proximal tubule.
Transport by epithelia with compliant lateral intercellular spaces: asymmetric oncotic effects across the rat proximal tubule.
复制标题
具有顺应性横向细胞间隙的上皮细胞的运输：大鼠近端小管的不对称胶体渗透作用。
DOI：
10.1152/ajprenal.1984.247.5.f848
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发表时间：
1984
期刊：
影响因子：
--
通讯作者：
Weinstein,AM
中科院分区：
文献类型：
--
作者：
Weinstein,AM
被认为是近端小管的数学模型，其中的横向细胞间空间扩张，在响应增加的间质压力和基底出口渗透性增加，作为结果的间隙扩大。间隙的近似分析模型揭示了这样的顺应性可能会引入不对称性的蛋白质onflammation力对跨上皮体积流量的影响的可能性。管周压力关闭间隙，增强间隙高渗性，从而显著增加体积重吸收（增强的上皮内溶质-溶剂偶联）。该模型还预测了上皮细胞的水渗透性（LP），盐反射系数和盐渗透性的下降，与管周蛋白的应用。当参数选择，以便代表大鼠近端小管，溶质渗透性的预测效果是相当的上皮细胞的电阻的变化。然而，当管腔溶液是轻微低渗的血液和近端重吸收已成为等渗，该模型显示相对较小的蛋白质的影响，这是依赖于细胞和紧密连接的渗透性和间隙顺应性的影响很小。这种模型的能力，以代表近端小管在体内的等渗盐和水的重吸收的小管周围蛋白质增强的质疑。
Mathematical models of the proximal tubule are considered in which the lateral intercellular spaces distend in response to increased interstitial pressures and basal outlet permeabilities increase as a result of interspace widening. An approximate analytical model of the interspace reveals the possibility that such compliance may introduce an asymmetry to the effect of protein oncotic forces on transepithelial volume flow. Peritubular oncotic forces close the interspace, enhance interspace hypertonicity, and thus substantially increase volume reabsorption (enhanced intraepithelial solute-solvent coupling). The model also predicts a decline in epithelial water permeability (Lp), salt reflection coefficient, and salt permeability, with the application of peritubular protein. When parameters are chosen so as to represent the rat proximal tubule, the predicted effect on solute permeability is comparable to the observed changes in electrical resistance of the epithelium. However, when the luminal solution is slightly hypotonic to blood and proximal reabsorption has become isosmotic, the models show relatively small protein effects, which are dependent upon cell and tight junction permeabilities and are little influenced by interspace compliance. The capability of such models to represent the peritubular protein enhancement of isosmotic salt and water reabsorption by the proximal tubule in vivo is questioned.