Rennke H G, Venkatachalam M A
J Clin Invest. 1979 Apr;63(4):713-7. doi: 10.1172/JCI109354.
Molecular parameters other than size and charge are likely to influence the filtration of macromolecules across the glomerular filter. We have studies, therefore, the glomerular permeability of macromolecules with widely different molecular configuration such as horseradish peroxidase, a plant glycoprotein with an isoelectric point in the physiologic pH range, and dextran, an uncharged sugar polymer of D-glucopyranose. Simultaneous fractional clearances were determined for both test macromolecules in five Wistar-Furth rats. The results indicate that for a molecular radius of 28.45 A, as measured by gel filtration, the sugar polymer has a fractional clearance of 0.483 on the average, exceeding that of the protein tracer, with a value of 0.068, by a factor less than 7. We conclude that other molecular parameters such as shape, flexibility, and deformability play important roles in the transport of macromolecules across the extracellular matrix that constitutes the glomerular filter.
除了大小和电荷之外，其他分子参数可能会影响大分子通过肾小球滤过膜的滤过。因此，我们研究了具有广泛不同分子构型的大分子的肾小球通透性，例如辣根过氧化物酶，一种等电点在生理pH范围内的植物糖蛋白，以及葡聚糖，一种D-吡喃葡萄糖的不带电荷的糖聚合物。在五只Wistar-Furth大鼠中同时测定了两种测试大分子的分数清除率。结果表明，通过凝胶过滤测量，对于分子半径为28.45 Å的情况，糖聚合物的平均分数清除率为0.483，超过蛋白质示踪剂的分数清除率（值为0.068），超过因子小于7。我们得出结论，其他分子参数，如形状、柔韧性和可变形性，在大分子穿过构成肾小球滤过膜的细胞外基质的转运中起重要作用。
