Gaiter A M, Paternoster G, Bonfant G, Caneparo G, Alloatti S
Servizio di Nefrologia e Dialisi della Valle d'Aosta.
Minerva Urol Nefrol. 1991 Jul-Sep;43(3):185-90.
The existence of an intraerythrocytic binding between haemoglobin and urea is known; it determines, in normals, a higher erythrocyte than plasma urea concentration; this binding, in vitro, is progressive for an urea concentration range of 10-400 mg/dl. The only data found relating to dialysis patients, are reported by Nolph et al.; they indicate a decrease in the plasma-blood urea ratio during the blood transit through the dialyzer and a different ratio in comparison with normals, but in our opinion the method used to measure urea concentration was unsuitable. We determined urea distribution ratios by measuring, in blood and plasma, water and urea concentration in uremic inflow and outflow blood samples during dialysis. Our data indicate 1) an increase in outflow erythrocyte water (H2Oe inflow: 0.659, H2Oe outflow: 0.671 P less than 0.01) induced by a different erythrocyte osmotic gradient; 2) a not different ratio between urea of erythrocyte water and urea of plasma water in inflow and outflow samples of dialysed patients and in normals (respectively 1.06, 1.16, 1.13 p = n.s.). Our data from normal and uremic patients are like those found by Murdaugh & Doyle and by Colton & Lowrie in normals.
血红蛋白与尿素之间存在红细胞内结合这一现象是已知的；在正常人中，它决定了红细胞中的尿素浓度高于血浆中的尿素浓度；在体外，对于10 - 400mg/dl的尿素浓度范围，这种结合是渐进性的。关于透析患者的唯一数据是由诺尔夫等人报道的；他们指出在血液通过透析器的过程中血浆 - 血液尿素比率降低，并且与正常人相比比率不同，但我们认为他们用于测量尿素浓度的方法不合适。我们通过在透析过程中测量尿毒症患者流入和流出血液样本中的血液和血浆中的水和尿素浓度来确定尿素分布比率。我们的数据表明：1）不同的红细胞渗透梯度导致流出红细胞内水增加（流入时红细胞内水：0.659，流出时红细胞内水：0.671，P＜0.01）；2）透析患者流入和流出样本以及正常人中，红细胞内水的尿素与血浆水的尿素比率无差异（分别为1.06、1.16、1.13，p = 无显著差异）。我们来自正常人和尿毒症患者的数据与默多克和多伊尔以及科尔顿和洛里在正常人中发现的数据相似。
