Kanwar Y S, Rosenzweig L J
J Cell Biol. 1982 May;93(2):489-94. doi: 10.1083/jcb.93.2.489.
The negative charges of the sulfated glycosaminoglycans (GAGs) of the glomerular basement membrane (GBM) were differentially neutralized by perfusin with high molarity buffers in order to determine whether or not these charges protect the GBM from being clogged by circulating plasma macromolecules. Progressive elimination of the negative charges resulted in clogging of the GBM by perfused native ferritin (NF) and bovine serum albumin as evidenced ultrastructurally by the increase in accumulation of NF in the GBM. In addition, the permeability of the GBM to 125I-insulin, a macromolecule which is normally freely permeable, and the glomerular filtration rate (as determined by [3H]inulin clearance) were markedly reduced after the GBM had been clogged with NF in the presence of high molarity buffer, thereby indicating that clogging severely reduces the ability of the GMB to act as a selective filter. These findings are consistent with the idea that the sulfated GAGs of the GBM serve as anticlogging agents.
为了确定肾小球基底膜（GBM）中硫酸化糖胺聚糖（GAGs）的负电荷是否能保护GBM不被循环血浆大分子堵塞，使用高摩尔浓度缓冲液灌注来差异性中和这些负电荷。负电荷的逐步消除导致灌注的天然铁蛋白（NF）和牛血清白蛋白堵塞GBM，超微结构显示GBM中NF积累增加可证明这一点。此外，在高摩尔浓度缓冲液存在的情况下，GBM被NF堵塞后，其对通常可自由通透的大分子125I-胰岛素的通透性以及肾小球滤过率（通过[3H]菊粉清除率测定）显著降低，从而表明堵塞严重降低了GBM作为选择性滤过器的能力。这些发现与GBM中的硫酸化GAGs作为抗堵塞剂的观点一致。
