Eksborg S, Persson B A, Allgen L G, Bergström J, Zimmerman L, Fürst P
Clin Chim Acta. 1978 Jan 2;82(1-2):141-50. doi: 10.1016/0009-8981(78)90037-2.
A selective analytical method for the determination of methylguanidine in plasma in biological fluids has been developed. Methylguanidine is extracted in a column to dichloromethane as an ion pair with hexanitrodiphenylamine (dipicrylamine). It is isolated from coextracted compounds by partition chromatography as the picrate ion-pair. The methylguanidine fraction is collected and after reextraction to a buffer solution the methylguanidine content is quantitatively determined photometrically as picrate. An absolute recovery of 95 +/- 5% was obtained in the concentration range 1.5-10 microgram/ml plasma. The concentration of methylguanidine in plasma was higher in uremic patients, (44.4 +/- 5.71 mumol/l in conservatively-treated and 42.4 +/- 7.87 mumol/l in dialysis-treated patients) than in normal subjects, (4.0 mumol/l), but still lower than reported by other investigators using non-specific methods and also lower than the concentrations found to be toxic in experimental animals. There was a significant correlation between methylguanidine and creatinine concentration but no correlation between methylguanidine and urea concentration in plasma. No obvious relation was found between plasma methylguanidine concentration and various uremic symptoms, mode of treatment or protein intake.
已开发出一种用于测定生物体液中血浆甲基胍的选择性分析方法。甲基胍在柱中以与六硝基二苯胺（二苦味胺）形成离子对的形式萃取到二氯甲烷中。通过分配色谱法作为苦味酸盐离子对从共萃取的化合物中分离出来。收集甲基胍馏分，再萃取到缓冲溶液中后，将甲基胍含量作为苦味酸盐通过光度法定量测定。在1.5 - 10微克/毫升血浆的浓度范围内，绝对回收率为95±5%。尿毒症患者血浆中甲基胍的浓度（保守治疗患者为44.4±5.71微摩尔/升，透析治疗患者为42.4±7.87微摩尔/升）高于正常受试者（4.0微摩尔/升），但仍低于其他使用非特异性方法的研究者报告的浓度，也低于在实验动物中发现的有毒浓度。血浆中甲基胍与肌酐浓度之间存在显著相关性，但与尿素浓度之间无相关性。未发现血浆甲基胍浓度与各种尿毒症症状、治疗方式或蛋白质摄入量之间有明显关系。
