Simultaneous assay of isotopic enrichment and concentration of guanidinoacetate and creatine by gas chromatography-mass spectrometry.
Simultaneous assay of isotopic enrichment and concentration of guanidinoacetate and creatine by gas chromatography-mass spectrometry.
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DOI：
10.1016/j.ab.2009.07.037
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发表时间：
2009-12-01
影响因子：
2.9
通讯作者：
Kalhan SC
中科院分区：
文献类型：
--
作者：
Kasumov T;Gruca LL;Dasarathy S;Kalhan SC
报道了一种用于动力学研究的气相色谱-质谱仪(GC-MS)同时测定血浆样品中胍基乙酸和肌酸的同位素富集度和浓度的方法。该方法基于制备双(三氟甲基)嘧啶甲酯的方法，是一种稳定、灵敏的方法。胍乙酸和肌酸的最低可测量m1和m3富集率分别为0.3%。浓度测量的校正曲线在0.5-250μM的胍基乙酸和2-500μM的肌酸范围内呈线性关系。该方法具有良好的批间和批内精密度、准确度和线性关系。将该技术应用于一名健康成人，通过预先恒速输注[1-13C]甘氨酸来测定体内肌酸的合成分数。结果发现，注入[1-13C]甘氨酸30min时，胍基乙酸的同位素丰度达到平台期，这表明其池规模较小或周转速度较快，或两者兼而有之。相反，肌酸的示踪剂出现缓慢(斜率：0.00097)，表明池大，肌酸合成速度慢。该方法可用于人体和动物体内肌酸合成速率的估算。
A gas chromatographic-mass spectrometric (GC-MS) method for the simultaneous measurement of isotopic enrichment and concentration of guanidinoacetic acid and creatine in plasma sample for kinetic studies is reported. The method, based on preparation of the bis(trifluoromethyl)-pyrimidine methyl ester derivatives of guanidinoacetic acid and creatine, is robust and sensitive. The lowest measurable m1 and m3 enrichment for guanidinoacetic acid and creatine, respectively, was 0.3%. The calibration curves for measurements of concentration were linear over a range of 0.5-250 μM guanidinoacetic acid and 2-500 μM for creatine. The method was reliable for inter-assay and intra-assay precision, accuracy and linearity. The technique was applied in a healthy adult to determine in vivo fractional synthesis rate of creatine using primed- constant rate infusion of [1-13C]glycine. It was found that isotopic enrichment of guanidinoacetic acid reached plateau by 30 min of infusion of [1-13C]glycine, indicating either a small pool size or a rapid turnover rate or both, of guanidinoacetic acid. In contrast, tracer appearance in creatin was slow (slope: 0.00097), suggesting a large pool size and a slow rate of synthesis of creatine. This method can be used to estimate rate of synthesis of creatine in-vivo in human and animal studies.
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影响因子：
3.9
作者：
DALY, MM
通讯作者：
DALY, MM
DOI：
10.1016/s0731-7085(98)00280-5
发表时间：
1998-12-01
影响因子：
3.4
作者：
Struys, EA;Jansen, EEW;Jakobs, C
通讯作者：
Jakobs, C
影响因子：
15.9
作者：
FITCH, CD;SINTON, DW
通讯作者：
SINTON, DW
影响因子：
5.5
作者：
Olsen, Steen;Aagaard, Per;Kjaer, Michael
通讯作者：
Kjaer, Michael
影响因子：
5
作者：
Valongo, C;Cardoso, ML;Vilarinho, L
通讯作者：
Vilarinho, L