Dynamic alterations of glomerular charge density in fixed rat kidneys suggest involvement of endothelial cell coat
Dynamic alterations of glomerular charge density in fixed rat kidneys suggest involvement of endothelial cell coat
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DOI：
10.1152/ajprenal.00227.2001
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发表时间：
2003-10-01
影响因子：
4.2
通讯作者：
Haraldsson, B
中科院分区：
文献类型：
--
作者：
Ciarimboli, G;Hjalmarsson, C;Haraldsson, B
在以前的论文中，我们发现低离子强度（I）可逆地降低了肾小球电荷密度，这表明电荷选择性屏障的体积增加。由于戊二醛使大多数结构刚性，我们认为离体灌注固定的大鼠肾脏是进一步分析的理想模型。用含有两种不同I（I = 151和34 mM）的FITC-Ficoll的白蛋白溶液灌注固定的肾脏。在正常I时，白蛋白的清除率分数（θ）为0.0049（SE-0.0017，+0.0027，n = 6），而类似大小的中性Ficoll（35.5埃）的θ显著高于0.104（SE 0.010，n = 5，P < 0.001）。在低I时，白蛋白的θ为0.0030（SE-0.0011，+0.0018，n = 6，与正常I时的θ（白蛋白）相比无显著性），Ficoll的θ（35.5埃）与正常I时相同，为0.104（SE 0.015，n = 6，与低I时的θ（白蛋白）相比P < 0.01）。根据异质带电纤维模型，低I使纤维密度从0.056降低到0.0315，表明78%的凝胶体积膨胀。我们的结论是：1）有一个显着的肾小球电荷屏障。2)即使在用戊二醛固定的肾脏中，低I溶液也会增加电荷屏障的体积。我们的研究结果表明，富含多糖的结构，如内皮细胞被，是肾小球屏障的关键组成部分。
In a previous paper, we found that low ionic strength (I) reversibly reduced the glomerular charge density, suggesting increased volume of the charge-selective barrier. Because glutaraldehyde makes most structures rigid, we considered the isolated, perfusion-fixed rat kidney to be an ideal model for further analysis. The fixed kidneys were perfused with albumin solutions containing FITC-Ficoll at two different Is (I = 151 and 34 mM). At normal I, the fractional clearance (theta) for albumin was 0.0049 (SE -0.0017, +0.0027, n = 6), whereas theta for neutral Ficoll(35.5Angstrom) of similar size was significantly higher 0.104 (SE 0.010, n = 5, P < 0.001). At low I, theta for albumin was 0.0030 ( SE -0.0011, +0.0018, n = 6, not significant from theta(albumin) at normal I) and theta for Ficoll(35.5 angstrom) was identical to that at normal I, 0.104 (SE 0.015, n = 6, P < 0.01 compared with theta(albumin) at low I). According to a heterogeneous charged fiber model, low I reduced the fiber density from 0.056 to 0.0315, suggesting a 78% gel volume expansion. We conclude that 1) there is a significant glomerular charge barrier. 2) Solutions with low I increase the volume of the charge barrier even in kidneys fixed with glutaraldehyde. Our findings suggest that polysaccharide-rich structures, such as the endothelial cell coat, are key components in the glomerular barrier.