白蛋白的分数清除率受其在肾脏滤过过程中降解的影响。

Fractional clearance of albumin is influenced by its degradation during renal passage.

作者信息

Osicka T M, Panagiotopoulos S, Jerums G, Comper W D

机构信息

Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia.

出版信息

Clin Sci (Lond). 1997 Dec;93(6):557-64. doi: 10.1042/cs0930557.

DOI:10.1042/cs0930557

Abstract

The fractional clearance of intact albumin as determined by fractionation of urine by gel chromatography gave a value of 3.9 +/- 1.6 x 10(-4) for the isolated perfused kidney and 2.1 +/- 0.6 x 10(-4) in vivo using ALZET osmotic pumps. 2. Albumin fractional clearance as measured by detection of the tritium label on the albumin molecule by radioactivity analysis gave a value of 7.5 +/- 3.9 x 10(-3) for the isolated perfused kidney and 2.3 +/- 0.9 x 10(-3) in vivo. 3. The major differences between assays that detect intact albumin compared with non-specific assays in the estimates of the fractional clearance of albumin can be explained by the degradation of approx. 90% of albumin to small peptides during its renal passage. This has been demonstrated by size exclusion chromatography of urine samples from experiments where (i) exogenous tritium-labelled albumin was used in isolated perfused kidneys, (ii) exogenous tritium-labelled albumin was administered intravenously and (iii) analysis was made with metabolically labelled endogenous albumin in vivo.

摘要

通过凝胶色谱法对尿液进行分级分离测定的完整白蛋白分数清除率，对于离体灌注肾的值为3.9±1.6×10⁻⁴，使用ALZET渗透泵在体内的值为2.1±0.6×10⁻⁴。2. 通过放射性分析检测白蛋白分子上的氚标记来测量的白蛋白分数清除率，对于离体灌注肾的值为7.5±3.9×10⁻³，在体内的值为2.3±0.9×10⁻³。3. 在白蛋白分数清除率的估计中，检测完整白蛋白的测定方法与非特异性测定方法之间的主要差异可以通过白蛋白在肾脏通过过程中约90%降解为小肽来解释。这已通过以下实验的尿液样本的尺寸排阻色谱法得到证明：(i) 在离体灌注肾中使用外源性氚标记白蛋白，(ii) 静脉注射外源性氚标记白蛋白，以及(iii) 对体内代谢标记的内源性白蛋白进行分析。