Olivetti G, Kithier K, Giacomelli F, Wiener J
Kidney Int. 1984 Apr;25(4):599-607. doi: 10.1038/ki.1984.63.
The effects of acute angiotensin II (AII) induced hypertension on renal hemodynamics, urinary excretory rates, and clearances of endogenous proteins, together with colloidal iron staining and numerical density of differently charged ferritins in glomerular basement membrane (GBM) have been studied. AII decreases para-aminohippurate clearance (63%) more than glomerular filtration rate (GFR) (42%), resulting in an increased filtration fraction (54%). Simultaneously, large increments in the excretory rates and clearances of albumin and IgG2a occur. The number of native ferritin particles per unit volume of GBM and its different layers increases significantly in both superficial and juxtamedullary glomeruli as a result of acute hypertension. In contrast, the number of cationized ferritin particles per unit volume of GBM as well as colloidal iron staining of GBM and adjacent cell membranes remain unchanged, irrespective of AII treatment. The results demonstrate that acute AII-induced hypertension enhances glomerular permeability to proteins of different size and shape in the absence of detectable alterations in the fixed negative charges of the GBM. Since both RBF and GFR are decreased, the increased transglomerular passage of proteins in acute hypertension appears to be due to an increase in the pore size of the glomerular filter, induced possibly by either high intracapillary pressure and/or a direct action of AII on GBM constituents.
研究了急性血管紧张素II（AII）诱导的高血压对肾血流动力学、尿排泄率以及内源性蛋白质清除率的影响，同时还研究了肾小球基底膜（GBM）的胶体铁染色以及不同电荷铁蛋白的数值密度。AII使对氨基马尿酸清除率降低（63%）的幅度大于肾小球滤过率（GFR）降低的幅度（42%），导致滤过分数增加（54%）。同时，白蛋白和IgG2a的排泄率和清除率大幅增加。由于急性高血压，浅表和近髓肾小球中每单位体积GBM及其不同层的天然铁蛋白颗粒数量显著增加。相比之下，无论是否进行AII处理，每单位体积GBM的阳离子化铁蛋白颗粒数量以及GBM和相邻细胞膜的胶体铁染色均保持不变。结果表明，在GBM固定负电荷无明显改变的情况下，急性AII诱导的高血压增强了肾小球对不同大小和形状蛋白质的通透性。由于肾血流量（RBF）和GFR均降低，急性高血压时蛋白质经肾小球滤过增加似乎是由于肾小球滤过器孔径增大，这可能是由高毛细血管内压和/或AII对GBM成分的直接作用所致。
