A modified cyanide-nitroprusside method for quantifying urinary cystine concentration that corrects for creatinine interference.
A modified cyanide-nitroprusside method for quantifying urinary cystine concentration that corrects for creatinine interference.
复制标题
一种改良的氰化物-硝普钠方法，用于定量尿胱氨酸浓度，校正肌酐干扰。
DOI：
10.1016/s0009-8981(99)00159-x
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发表时间：
1999
期刊：
影响因子：
--
通讯作者：
Coe,FL
中科院分区：
文献类型：
--
作者：
Nakagawa,Y;Coe,FL
胱氨酸尿症是一种遗传性疾病，临床上通过检测尿液中的胱氨酸来诊断。使用氰化钠和硝普钠的比色法是用于检测胱氨酸尿症的简单定性试验。几种比色法已被提出用于胱氨酸的定量分析，然而，我们发现，他们都是令人满意的，因为结果是不重复的。结果不可重现的原因是：（1）胱氨酸转化为半胱氨酸的还原时间不足，（2）肌酐的干扰。在这份报告中，我们提出了一种方法来定量尿中胱氨酸。我们还发现，抗坏血酸和氯化铁，而不是氯化锌，干扰显色反应。用此方法分析了15例正常人（男10例，女5例）和12例胱氨酸结石患者（男5例，女7例）的尿液。将该方法与市售尿液质控品进行比较。只有卡托普利在521 nm处显示出剂量依赖性反应和颜色强度。巯基和D-青霉胺对胱氨酸的测定影响不大。
Cystinuria, an inherited disease, is clinically diagnosed by detecting cystine in urine. A colorimetric method using sodium cyanide and sodium nitroprusside is a simple qualitative test used to detect cystinuria. Several colorimetric methods have been proposed for quantitative analysis of cystine; however, we found that none of them were satisfactory because the results were not reproducible. The causes of non-reproducible results were: (1) insufficient reduction time for conversion of cystine to cysteine, and (2) the interference of creatinine. In this report, we present a method to quantitate cystine in urine. We also found that ascorbic acid and ferric chloride, but not zinc chloride, interfered with the color reaction. Using this method, 15 normal urine samples (10 males and 5 females) and 12 cystine stone forming patients’ (5 males and 7 females) urine were analyzed. The method was compared to commercially available urine controls. Only captopril showed a dose dependent response and color intensity at 521 nm. Thiola and D-penicillamine showed little effect on cystine determination.