Metabolism of albumin and immunoglobulins in the nephrotic syndrome.
Metabolism of albumin and immunoglobulins in the nephrotic syndrome.
复制标题
肾病综合征中白蛋白和免疫球蛋白的代谢。
DOI：
10.1159/000168192
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发表时间：
1990
影响因子：
4.2
通讯作者：
alBander,H
中科院分区：
文献类型：
--
作者：
Kaysen,GA;alBander,H
肾病综合征的特征是白蛋白和其他中等分子量的血清蛋白的尿排泄增加，伴随着它们的血清浓度降低。白蛋白合成在mRNA合成水平上增加，以响应降低的血清onglutinase压力。然而，这些反应的幅度取决于膳食蛋白，不足以使血清白蛋白正常化。白蛋白催化剂的绝对速率降低，有助于使血清白蛋白储存正常化，但与其他低白蛋白血症状态相比，白蛋白催化剂的分数速率增加。这一观察结果与肾病中肾组织蛋白酶活性增加导致总白蛋白酶活性增加的假设一致。与白蛋白一样，IgG在尿液中丢失，其血清浓度降低，并且其catalysts的分数率增加，这表明在蛋白尿存在的情况下肾脏有助于IgG catalysts。IgG合成在肾病综合征中以可变方式响应，并且可能减少，从而有助于其血清浓度降低。相反，高分子量免疫球蛋白IgM的血清浓度增加，多种高分子量肝源性蛋白的血清浓度也增加。目前尚不清楚血清IgM浓度升高的机制，但这种反应有助于保护血清蛋白浓度和血清压力。
The nephrotic syndrome is characterized by the increased urinary excretion of albumin and of other serum proteins of intermediate molecular weight accompanied by a decrease in their serum concentration. Albumin synthesis is increased at the level of mRNA synthesis in response to decreased serum oncotic pressure. However, the magnitude of these responses is dependent upon dietary protein and is insufficient to normalize serum albumin. The absolute rate of albumin catabolism is decreased, serving to normalize serum albumin stores, but in contrast to what occurs in other hypoalbuminemic states, the fractional rate of albumin catabolism is increased. This observation is consistent with a hypothesis that increased renal catabolism contributes to total albumin catabolism in nephrosis. Like albumin, IgG is lost in the urine, its serum concentration is decreased, and the fractional rate of its catabolism is increased, suggesting that the kidney contributes to IgG catabolism in the presence of proteinuria. IgG synthesis responds in a variable fashion in the nephrotic syndrome, and may be decreased, thus contributing to its reduced serum concentration. In contrast, the serum concentration of the high-molecular-weight immunoglobulin IgM is increased, as is the serum concentration of a variety of high-molecular-weight liver-derived proteins. It is unknown by what mechanism serum IgM concentration is increased, but this response serves to defend serum protein con centration and oncotic pressure.