Adler S, Baker P, Pritzl P, Couser W G
J Lab Clin Med. 1985 Jul;106(1):1-11.
Reduction of the negative charge of the glomerular capillary wall alters its charge- and size-selective properties. To investigate the effect of alteration in glomerular charge properties on antibody localization, we prepared cationic and anionic fractions of antibodies to subepithelial and glomerular basement membrane (GBM) antigens, and compared their deposition in normal rats and rats treated with protamine sulfate or aminonucleoside of puromycin to reduce capillary wall charge. IgG antibodies were eluted from kidneys of rats with active Heymann's nephritis (AICN), passive Heymann's nephritis (PHN), or anti-GBM nephritis (NTN), separated into cationic and anionic fractions, and radiolabeled with iodine 125 or iodine 131. Relative antibody content of each fraction was determined by incubation with an excess of glomerular antigen. Varying amounts of cationic and anionic IgG eluted from kidneys of rats with AICN or PHN were injected into 24 normal or protamine sulfate-treated rats. Glomerular binding of all antibodies was highly correlated with IgG delivery to the kidney. The ratio of cationic to anionic antibody deposited in the glomeruli of normal rats after 4 hours was 1.08 +/- 0.07 for AICN eluate and 0.37 +/- 0.04 for PHN eluate. The ratios were not significantly different in animals pretreated with protamine sulfate (1.15 +/- 0.06 and 0.44 +/- 0.06, respectively; P greater than 0.05). Varying amounts of cationic and anionic IgG eluted from kidneys of rats with NTN were injected into 10 normal rats and four rats treated with aminonucleoside of puromycin. Glomerular binding of antibody was again highly correlated with IgG delivery to the kidney. The ratio of cationic to anionic antibody deposited in the glomeruli of normal rats after 1 hour was 1.03 +/- 0.06, and was not significantly altered in rats treated with aminonucleoside of puromycin (1.05 +/- 0.03, P greater than 0.5). Proteinuria in PHN rats was also unaffected by treatment with protamine sulfate for 5 days (controls: 68 +/- 21 mg/day; protamine sulfate-treated: 65 +/- 14 mg/day; n = 25, P greater than 0.08). These results demonstrate that treatment to reduce glomerular polyanion does not significantly alter the ratio of cationic to anionic antibodies to fixed glomerular antigens that deposit in the glomerulus, or reduce proteinuria caused by deposition of antibody to a fixed subepithelial antigen.
肾小球毛细血管壁负电荷的减少会改变其电荷和大小选择性特性。为了研究肾小球电荷特性改变对抗体定位的影响，我们制备了针对上皮下和肾小球基底膜（GBM）抗原的抗体的阳离子和阴离子组分，并比较了它们在正常大鼠以及用硫酸鱼精蛋白或嘌呤霉素氨基核苷处理以降低毛细血管壁电荷的大鼠中的沉积情况。从患有活动性海曼肾炎（AICN）、被动性海曼肾炎（PHN）或抗GBM肾炎（NTN）的大鼠肾脏中洗脱IgG抗体，分离成阳离子和阴离子组分，并用碘125或碘131进行放射性标记。通过与过量的肾小球抗原孵育来测定每个组分的相对抗体含量。将从患有AICN或PHN的大鼠肾脏中洗脱的不同量的阳离子和阴离子IgG注射到24只正常或硫酸鱼精蛋白处理的大鼠中。所有抗体的肾小球结合与IgG输送到肾脏的情况高度相关。正常大鼠肾小球中沉积的阳离子与阴离子抗体的比例，对于AICN洗脱液在4小时后为1.08±0.07，对于PHN洗脱液为0.37±0.04。在用硫酸鱼精蛋白预处理的动物中，这些比例没有显著差异（分别为1.15±0.06和0.44±0.06；P大于0.05）。将从患有NTN的大鼠肾脏中洗脱的不同量的阳离子和阴离子IgG注射到10只正常大鼠和4只用嘌呤霉素氨基核苷处理的大鼠中。抗体的肾小球结合再次与IgG输送到肾脏的情况高度相关。正常大鼠肾小球中沉积的阳离子与阴离子抗体的比例在1小时后为1.03±0.06，在用嘌呤霉素氨基核苷处理的大鼠中没有显著改变（1.05±0.03，P大于0.5）。PHN大鼠的蛋白尿在用硫酸鱼精蛋白处理5天后也未受影响（对照组：68±21毫克/天；硫酸鱼精蛋白处理组：65±14毫克/天；n = 25，P大于0.08）。这些结果表明，降低肾小球多阴离子的处理不会显著改变沉积在肾小球中的阳离子与阴离子抗体与固定肾小球抗原的比例，也不会减少由抗体沉积到固定上皮下抗原所导致的蛋白尿。
