Steele W H, Lawrence J R, Elliott H L, Whiting B
Eur J Clin Pharmacol. 1979 Feb 19;15(1):69-71. doi: 10.1007/BF00563560.
Protein binding of phenytoin was assesed in one patient with dialysis encephalopathy before and after haemodialysis. Phenytoin concentrations were measured by radioimmunoassay and continuous ultrafiltration was used to assess phenytoin binding. At a serum concentration of 60 micromol.1-1 the percentage of phenytoin bound to serum albumin was considerably lower in the patient serum (79.95% predialysis; 92.09% postdialysis) than that in three normal sera (97.90 +/- 0.17%). Analysis of Scatchard plots indicated two classes of binding sites. In class I both the affinity and capacity for binding phenytoin were reduced in the pre and post-dialysis serum, whereas in class II the capacity of the uraemic serum was increased although the intrinsic association constant was greatly reduced. It was concluded that in vivo haemodialysis is associated with large fluctuations in the protein binding of phenytoin, in which the concentration of endogenous dialysible metabolites are strongly implicated.
在一名患有透析性脑病的患者进行血液透析前后，评估了苯妥英的蛋白结合情况。通过放射免疫测定法测量苯妥英浓度，并使用连续超滤来评估苯妥英的结合情况。在血清浓度为60微摩尔·升⁻¹时，患者血清中与血清白蛋白结合的苯妥英百分比（透析前79.95%；透析后92.09%）明显低于三份正常血清中的百分比（97.90±0.17%）。Scatchard图分析表明存在两类结合位点。在I类中，透析前和透析后血清中结合苯妥英的亲和力和容量均降低，而在II类中，尿毒症血清的容量增加，尽管内在缔合常数大大降低。得出的结论是，体内血液透析与苯妥英的蛋白结合大幅波动有关，其中内源性可透析代谢物的浓度起着重要作用。
