Nolph K, Felts J, Moore R, Van Stone J
Int Urol Nephrol. 1978;10(1):59-64. doi: 10.1007/BF02082794.
It has been proposed that urea and creatinine may bind to red cell constituents. In the present studies, whole blood and plasma concentrations of urea and creatinine were compared using autoanalyzer techniques (that require solutes to pass through a dialysis membrane) and manual techniques (with no dialysis membrane). Blood samples from 11 normal and 10 azotemic subjects were studied. Concentration differences between plasma water and red cell water for these solutes were significant in normals with standard manual but not with autoanalyzer methods. Accordingly, red cell water concentrations in normals were greater with manual methods than with autoanalyzer methods. In azotemics, differences between red cell and plasma water concentrations and differences in red cell water concentrations between methods were proportionately less. The findings suggest that accumulation of these solutes in the red cell in azotemia is predominantly in the freely diffusable form. Any chemical interference of red cell proteins and/or solute binding to red cell constituents yields significant discrepancies between manual and autoanalyzer methods only at lower BUN and creatinine concentrations.
有人提出尿素和肌酐可能会与红细胞成分结合。在本研究中，使用自动分析仪技术（需要溶质通过透析膜）和手工技术（不使用透析膜）比较了全血和血浆中尿素和肌酐的浓度。研究了11名正常受试者和10名氮质血症受试者的血样。对于这些溶质，正常受试者中血浆水和红细胞水之间的浓度差异在标准手工方法中显著，但在自动分析仪方法中不显著。因此，正常受试者中手工方法测得的红细胞水浓度高于自动分析仪方法。在氮质血症患者中，红细胞和血浆水浓度之间的差异以及不同方法之间红细胞水浓度的差异相应较小。这些发现表明，氮质血症时红细胞中这些溶质的积累主要以可自由扩散的形式存在。只有在较低的尿素氮和肌酐浓度下，红细胞蛋白的任何化学干扰和/或溶质与红细胞成分的结合才会导致手工方法和自动分析仪方法之间出现显著差异。
