Melnick G F, Ladoulis C T, Cavallo T
Am J Pathol. 1981 Nov;105(2):114-20.
To verify whether an increase in glomerular permeability precedes the deposition of immune complexes in the capillary wall, the following were studied in mice with lupus nephritis: 1) urinary proteins; 2) glomerular transfer of IgG, albumin, and anionic ferritin (AF) (isoelectric point, 4.2-4.6); and 3) anionic groups of the capillary wall as detected by binding of cationized ferritin (CF) (isoelectric point, 7.5-8.6). The glomeruli were investigated by immunofluorescence, immunoelectron, and transmission electron-microscopic studies. Urinary proteins were quantitated and characterized by electrophoresis. When mice were 5 months of age, (the time at which pathologic proteinuria was first detected), immune deposits were few and were confined to the mesangium. Although AF molecules were largely retained at the level of the lamina rara interna, focal leakage of albumin and IgG was detected across capillary walls that were not found to contain immune deposits. Focal and irregular loss of anionic groups, reflected by decreased binding of CF molecules, occurred in the laminae rarae of the basement membrane. Foot processes of glomeruli incubated with CF showed no loss of polyanion. We conclude that the increase in glomerular permeability that precedes deposition of immune complexes is due, in part, to focal loss of anionic groups of the basement membrane.
为了验证肾小球通透性增加是否先于免疫复合物在毛细血管壁沉积，我们对狼疮性肾炎小鼠进行了以下研究：1）尿蛋白；2）IgG、白蛋白和阴离子铁蛋白（AF）（等电点4.2 - 4.6）的肾小球转运；3）通过阳离子化铁蛋白（CF）（等电点7.5 - 8.6）结合检测的毛细血管壁阴离子基团。通过免疫荧光、免疫电子和透射电子显微镜研究对肾小球进行检查。尿蛋白通过电泳进行定量和鉴定。当小鼠5个月大时（首次检测到病理性蛋白尿的时间），免疫沉积物很少，且局限于系膜。虽然AF分子大多保留在内疏松层水平，但在未发现有免疫沉积物的毛细血管壁上检测到白蛋白和IgG的局灶性渗漏。基底膜疏松层出现CF分子结合减少所反映的阴离子基团局灶性和不规则性丢失。用CF孵育的肾小球足突未显示多阴离子丢失。我们得出结论，免疫复合物沉积之前肾小球通透性的增加部分是由于基底膜阴离子基团的局灶性丢失。
