Department of Biochemistry and Immunology, Birmingham Heart of England NHS Foundation Trust, Bordesley Green East, Birmingham B9 5SS, UK.
Ann Clin Biochem. 2011 May;48(Pt 3):223-32. doi: 10.1258/acb.2010.010182. Epub 2011 Feb 25.
Mevalonic acid (MVA) is synthesized at an early and rate-limiting step in the biosynthesis of cholesterol by the enzyme hydroxymethylglutaryl coenzyme A (HMG-CoA) reductase, and is a useful measure of statin efficacy or treatment. A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the measurement of serum MVA has been developed.
Following the in vitro conversion of MVA to mevalonic acid lactone (MVAL) in the serum, MVAL and a deuterated internal standard were extracted using an online solid-phase extraction procedure. Chromatographic separation was achieved using a Luna PFP column (Phenomenex), with enhanced selectivity and improved resolution for polar compounds. A gradient system was used, with mobile phase comprising methanol and water (5 mmol/L ammonium formate buffer, pH 2.5). Analysis was performed using an API 5000 tandem mass spectrometer (Applied Biosystems) in positive electrospray ionization mode.
The method showed excellent recoveries (98 ± 8%) and imprecision (intra-assay coefficient of variation of 2.2% [6.5 ng/mL] and 2.6% [10.5 ng/mL], and inter-assay coefficient of variation of 9% [10.5 ng/mL]). The assay provides a calibration range up to 50 ng/mL with a limit of detection at 0.1 ng/mL.
A simple, rapid and analytically specific method has been developed for the measurement of serum MVA, in the form of MVAL. The high analytical sensitivity of the method allows for accurate quantitation of MVAL in serum samples, both at the endogenous levels found in healthy individuals and in statin-treated patients where normal levels are expected to be greatly reduced through the inhibition of HMG-CoA reductase.
羟甲基戊二酰辅酶 A（HMG-CoA）还原酶在胆固醇生物合成的早期和限速步骤中合成甲羟戊酸（MVA），是评估他汀类药物疗效或治疗的有用指标。已经开发出一种用于测量血清 MVA 的液相色谱-串联质谱（LC-MS/MS）方法。
在血清中体外将 MVA 转化为甲羟戊酸内酯（MVAL）后，使用在线固相萃取程序提取 MVAL 和氘代内标。使用 Luna PFP 柱（Phenomenex）实现色谱分离，该柱对极性化合物具有增强的选择性和更好的分辨率。使用梯度系统，流动相由甲醇和水（5 mmol/L 甲酸铵缓冲液，pH 2.5）组成。使用 API 5000 串联质谱仪（Applied Biosystems）在正电喷雾电离模式下进行分析。
该方法显示出良好的回收率（98±8%）和精密度（内标法变异系数为 2.2%[6.5 ng/mL]和 2.6%[10.5 ng/mL]，以及 9%[10.5 ng/mL]的日间变异系数）。该测定法提供高达 50 ng/mL 的校准范围，检测限为 0.1 ng/mL。
已经开发出一种简单、快速且具有分析特异性的方法，用于测量 MVAL 形式的血清 MVA。该方法具有很高的分析灵敏度，可准确定量健康个体内源性水平以及他汀类药物治疗患者中的 MVAL，后者预计通过抑制 HMG-CoA 还原酶而使正常水平大大降低。
