Langsdorf L J, Zydney A L
Department of Chemical Engineering, University of Delaware, Newark 19716.
Blood. 1993 Feb 1;81(3):820-7.
Even though there is extensive evidence that uremia affects the fragility and deformability of red blood cells (RBCs), essentially all data on the RBC membrane permeability have been obtained with nonuremic blood. Permeability data were obtained for creatinine and uric acid, two metabolites of interest in hemodialysis, using a stirred ultrafiltration device with direct cell- and protein-free sampling. Experiments examined the effects of temperature and suspending phase on solute transport for both normal and uremic blood cells. Creatinine and uric acid transport from normal RBCs at 37 degrees C were characterized by saturation half-times of 40 +/- 10 minutes and 54 +/- 12 minutes, respectively. The corresponding half-times for uremic cells were significantly longer, 94 +/- 26 minutes and 180 +/- 38 minutes. Data indicated that the slower rate of creatinine transport in uremic blood was caused by an alteration in the RBC membrane, while the reduction in uric acid transport was associated with alterations in the uremic plasma. The temperature dependence of the RBC permeability was also much less pronounced for uremic cells for both solutes. These results provide important insights into the effects of uremia on the RBC membrane permeability, and have important implications for dialysis.
尽管有大量证据表明尿毒症会影响红细胞（RBC）的脆性和可变形性，但基本上所有关于红细胞膜通透性的数据都是通过非尿毒症血液获得的。使用带有直接无细胞和无蛋白采样的搅拌超滤装置，获得了血液透析中两种感兴趣的代谢物肌酐和尿酸的通透性数据。实验研究了温度和悬浮相对正常和尿毒症血细胞溶质转运的影响。在37摄氏度时，正常红细胞中肌酐和尿酸的转运特征分别为饱和半衰期40±10分钟和54±12分钟。尿毒症细胞的相应半衰期明显更长，分别为94±26分钟和180±38分钟。数据表明，尿毒症血液中肌酐转运速率较慢是由红细胞膜的改变引起的，而尿酸转运的降低与尿毒症血浆的改变有关。对于两种溶质，尿毒症细胞中红细胞通透性对温度的依赖性也明显较小。这些结果为尿毒症对红细胞膜通透性的影响提供了重要见解，并对透析具有重要意义。
