RENAL HANDLING OF LOW MOLECULAR WEIGHT PROTEINS .1. L-CHAIN METABOLISM IN EXPERIMENTAL RENAL DISEASE
RENAL HANDLING OF LOW MOLECULAR WEIGHT PROTEINS .1. L-CHAIN METABOLISM IN EXPERIMENTAL RENAL DISEASE
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DOI：
10.1172/jci106562
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发表时间：
1971-01-01
影响因子：
15.9
通讯作者：
STROBER, W
中科院分区：
文献类型：
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作者：
MOGIELNICKI, RP;WALDMANN, TA;STROBER, W
在正常小鼠、患有马来酸钠诱导的肾小管疾病但肾小球滤过率 (GFR) 正常的小鼠以及同时患有肾小管疾病和 GFR 降低的小鼠中研究了免疫球蛋白 L 链代谢。在仅患有肾小管疾病的小鼠中，L 链的蛋白尿率增加了一倍，尽管 L 链从这些动物的循环中消失的总体速率没有变化。这与患有肾小管疾病和肾小球滤过率降低的小鼠的发现形成鲜明对比，其中L链消失率显着降低。这些发现表明，在正常状态下，L链和可能的其他类似大小的蛋白质穿过肾小球，并被卷曲肾小管细胞大量吸收和分解代谢。在肾小管蛋白尿状态下，这种相关的摄取分解代谢功能失效，导致尿液排泄增加，但这些蛋白质的血清水平和周转率正常。在肾小球滤过减少的尿毒症状态下，输送到肾小管腔内的小蛋白质较少，排泄和分解代谢过程也减少。这导致小蛋白质的存活时间延长，并解释了在尿毒症中观察到的这些蛋白质的血清浓度升高的原因。
Immunoglobulin L-chain metabolism was studied in normal mice, mice with sodium maleate-induced renal tubular disease but normal glomerular filtration rate (GFR), and mice with both tubular disease and decreased GFR. The proteinuric rate of L-chain was increased twofold in mice with tubular disease alone though there was no alteration in the over-all rate at which L-chain disappeared from the circulation in these animals. This was in sharp contrast to findings in mice with tubular diseaseanda decreased glomerular filtration rate in which L-chain disappearance rates were markedly reduced. These findings demonstrate that in the normal state, L-chain and presumably other proteins of similar size pass through the glomerulus and are avidly taken up and catabolized by the convoluted tubular cells. In tubular proteinuric states this linked uptake-catabolic function fails, resulting in elevated urinary excretion but normal serum levels and turnover rates of these proteins. In uremic states with decreased glomerular filtration, less small protein is delivered into the tubular lumen and the processes of excretion and catabolism are reduced. This results in prolongation of the survival of small proteins and explains the elevated serum concentrations of these proteins observed in uremia.Images