Urinary galactitol and galactonate quantified by isotope-dilution gas chromatography-mass spectrometry.
Urinary galactitol and galactonate quantified by isotope-dilution gas chromatography-mass spectrometry.
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通过同位素稀释气相色谱-质谱法对尿半乳糖醇和半乳糖酸盐进行定量。
DOI：
10.1016/j.cca.2005.10.015
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发表时间：
2006
期刊：
影响因子：
--
通讯作者：
Segal,Stanton
中科院分区：
文献类型：
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作者：
Yager,Claire;Wehrli,Suzanne;Segal,Stanton
尿半乳糖醇的测定已被用于监测半乳糖血症治疗中饮食疗法的充分性。我们设计了一种气相色谱质谱（GC/MS）同位素稀释法，用于同时定量尿液半乳糖醇和另一种替代途径产物，方法制备了三甲基硅烷基（TMS）衍生物，并以d-[UL-13 C]半乳糖醇和d-[UL-13 C]半乳糖酸酯为内标物进行GC/MS分析。用此方法得到的结果进行了比较，与那些确定的GC方法半乳糖醇和半乳糖酸的NMR方法。用同位素稀释法测定了33例正常人尿中半乳糖醇和半乳糖酸的含量。对其中6例尿标本、18例典型半乳糖血症患者和19例变异型半乳糖血症患者沿着尿标本的半乳糖醇测定结果与建立的气相色谱法进行了比较。15例半乳糖血症患者尿中半乳糖酸的测定结果与已建立的核磁共振技术进行了比较，结果表明，该方法线性范围达200 nmol，半乳糖醇和半乳糖酸的检测下限分别为1.1 nmol（1.75 mmol/mol肌酐）和0.8 nmol（1.28 mmol/mol肌酐）。半乳糖醇的批内和批间不精密度范围为2.1-6.7%，半乳糖酸盐为3.5-8.0%。在正常和半乳糖血症患者中，两种代谢物的排泄均呈年龄依赖性。在12例1岁以下受试者的正常尿液中，半乳糖醇的值范围为8-107 mmol/mol Cr，7例6岁以上受试者的值范围为2-5 mmol/mol Cr。在1岁以下，半乳糖酸盐的范围是不可检测到的231，在6岁以上的组中，不可检测到25 mmol/mol Cr。在1岁以下的半乳糖血症中，半乳糖醇和半乳糖酸的值分别为397-743和92-132 mmol/mol Cr，而在9名6岁以上的患者中，半乳糖醇和半乳糖酸的值分别为125-274 mmol/mol Cr和17-46 mmol/mol Cr。MS方法能够同时测定尿液半乳糖醇和半乳糖酸，并且在评估半乳糖负荷所需的宽浓度范围内是精确和有用的。半乳糖血症患者。
BACKGROUNDMeasurements of urine galactitol have been used to monitor the adequacy of diet therapy in the treatment of galactosemia. We have devised a gas chromatographic mass spectrometry (GC/MS) isotope-dilution method for the simultaneous quantification of urine galactitol and another alternate pathway product, galactonate.METHODSWe prepared trimethylsilyl (TMS) derivatives and used d-[UL-13C]galactitol and d-[UL-13C]galactonate as the internal standard for GC/MS. Results obtained with this method were compared with those determined by the established GC method for galactitol and the NMR method for galactonate. Thirty-three normal urine specimens were analyzed by the isotope dilution technique for galactitol and galactonate. Results of galactitol in 6 of these urine specimens along with 18 from classic galactosemics and 19 variant galactosemics were compared with the established GC method. Results for galactonate in 15 urine specimens from galactosemics were compared to the established NMR technique.RESULTSThe method was linear up to 200 nmol with lower limits of detection of 1.1 nmol (1.75 mmol/mol creatinine) (Cr) and 0.8 nmol (1.28 mmol/mol Cr) for galactitol and galactonate, respectively. Intra- and Interassay imprecision ranged from 2.1–6.7% for galactitol and 3.5–8.0% for galactonate. The excretion of both metabolites was age dependent in both normal and galactosemics. In 12 normal urines from subjects under 1 year, values for galactitol ranged from 8–107 mmol/mol Cr, and in 7 over age 6, ranged from 2–5 mmol/mol Cr. Under 1 year, the range for galactonate was non-detectable to 231 and in the over 6 years group non-detectable to 25 mmol/mol Cr. In galactosemics under 1 year, the value for galactitol ranged from 397–743 and for galactonate 92–132 mmol/mol Cr while in nine patients over age 6 the range was 125–274 mmol/mol Cr for galactitol and 17–46 mmol/mol Cr for galactonate.CONCLUSIONSThe GC/MS method enables the simultaneous determination of urine galactitol and galactonate and is precise and useful over the wide range of concentrations needed to assess the galactose burden in patients with galactosemia.