Saarland University Hospital, Department of Clinical Chemistry and Laboratory Medicine, Building 57, 66421 Homburg/Saar, Germany.
J Chromatogr B Analyt Technol Biomed Life Sci. 2010 Dec 15;878(32):3338-44. doi: 10.1016/j.jchromb.2010.10.016. Epub 2010 Oct 23.
Disorders in choline metabolism are related to disease conditions. We developed a stable-isotope dilution ultra performance liquid chromatography-mass spectrometry (UPLC-MS/MS) method for the simultaneous quantification of acetylcholine (ACh), betaine, choline, and dimethylglycine (DMG). We used this method to measure concentrations of the analytes in plasma and urine in addition to other biological fluids after a protein precipitation by acetonitrile. The detection limits were between 0.35 nmol/L (for ACh in urine) and 0.34 μmol/L (for betaine in urine). ACh concentrations were not detectable in plasma. Intraassay and interassay coefficient of variation (CVs) were all <10.0% in biological fluids, except for DMG in cerebrospinal fluid (CV=12.44%). Mean recoveries in urine pool samples were between 99.2% and 103.9%. The urinary excretion of betaine, choline, and DMG was low, with approximately 50.0% higher excretion of choline in females compared to males. Median urinary excretion of ACh were 3.44 and 3.92 μmol/mol creatinine in males and females, respectively (p=0.689). Plasma betaine concentrations correlated significantly with urinary excretions of betaine (r=0.495, p=0.027) and choline (r=0.502, p=0.024) in females. Plasma choline concentrations correlated significantly with urinary excretion of ACh in males (r=0.419, p=0.041) and females (r=0.621, p=0.003). The new method for the simultaneous determination of ACh, betaine, choline, and DMG is sensitive, precise, and fast enough to be used in clinical investigations related to the methylation pathway.
胆碱代谢紊乱与疾病状况有关。我们开发了一种稳定同位素稀释超高效液相色谱-质谱联用（UPLC-MS/MS）方法，用于同时定量检测乙酰胆碱（ACh）、甜菜碱、胆碱和二甲氨基乙醇（DMG）。我们使用该方法通过乙腈沉淀蛋白来测量血浆和尿液以及其他生物液体中分析物的浓度。检测限在 0.35 nmol/L（尿液中的 ACh）和 0.34 μmol/L（尿液中的甜菜碱）之间。在血浆中无法检测到 ACh 浓度。除了脑脊液中的 DMG（CV=12.44%）外，生物液体中的内标和间标 CV 均<10.0%。尿液池样品中的平均回收率在 99.2%到 103.9%之间。甜菜碱、胆碱和 DMG 的尿排泄量较低，女性的胆碱排泄量比男性高约 50.0%。男女的 ACh 尿排泄中位数分别为 3.44 和 3.92 μmol/mol 肌酐（p=0.689）。女性血浆甜菜碱浓度与尿中甜菜碱（r=0.495，p=0.027）和胆碱（r=0.502，p=0.024）排泄量呈显著相关。男性和女性血浆胆碱浓度与 ACh 尿排泄量呈显著相关（r=0.419，p=0.041 和 r=0.621，p=0.003）。这种同时测定 ACh、甜菜碱、胆碱和 DMG 的新方法灵敏、准确、快速，足以用于与甲基化途径相关的临床研究。
