Layton G J, Jerums G
Department of Medicine, University of Melbourne, Austin Hospital, Heidelberg, Victoria, Australia.
Kidney Int. 1988 Mar;33(3):673-6. doi: 10.1038/ki.1988.52.
Two independent techniques have been used to study the renal clearances of nonenzymatically glycated albumin and nonglycated albumin in normal and streptozotocin-induced diabetic rats, 16 to 24 weeks after the onset of diabetes. In the first technique, serum and urinary endogenous glycated and nonglycated albumin were separated using m-aminophenylboronate affinity chromatography and subsequently quantified by radioimmunoassay. Endogenous glycated albumin was cleared approximately twofold faster than nonglycated albumin in normal and diabetic rats. However, no difference was observed in the glycated albumin/nonglycated albumin clearance ratios (Cga/Calb) in normal and diabetic rats, respectively (2.18 +/- 0.39 vs 1.83 +/- 0.22, P greater than 0.05). The second technique measured the renal clearance of injected 125I-labelled glycated albumin and 125I-labelled albumin. The endogenous results were supported by the finding that 125I-labelled glycated albumin was cleared more rapidly than 125I-labelled albumin in normal (P less than 0.01) and diabetic (P less than 0.05) rats. The Cga/Calb ratio calculated for the radiolabelled albumins was 1.4 and 2.0 in normal and diabetic rats, respectively. This evidence suggests that nonenzymatic glycation of albumin increases its renal clearance to a similar degree in normal and diabetic rats.
在糖尿病发病16至24周后，运用两种独立技术研究了正常大鼠和链脲佐菌素诱导的糖尿病大鼠中非酶糖基化白蛋白和非糖基化白蛋白的肾脏清除率。在第一种技术中，使用间氨基苯硼酸亲和色谱法分离血清和尿液中的内源性糖基化和非糖基化白蛋白，随后通过放射免疫测定法定量。在正常大鼠和糖尿病大鼠中，内源性糖基化白蛋白的清除速度比非糖基化白蛋白快约两倍。然而，正常大鼠和糖尿病大鼠中糖基化白蛋白/非糖基化白蛋白清除率（Cga/Calb）分别未观察到差异（2.18±0.39对1.83±0.22，P＞0.05）。第二种技术测量了注射的125I标记的糖基化白蛋白和125I标记的白蛋白的肾脏清除率。在正常大鼠（P＜0.01）和糖尿病大鼠（P＜0.05）中，125I标记的糖基化白蛋白比125I标记的白蛋白清除更快，这一发现支持了内源性结果。正常大鼠和糖尿病大鼠中放射性标记白蛋白的Cga/Calb比值分别为1.4和2.0。这一证据表明，在正常大鼠和糖尿病大鼠中，白蛋白的非酶糖基化使其肾脏清除率增加到相似程度。
