背景:由于胆碱之间的密切关系,左旋肉碱,甜菜碱及其肠道微生物代谢产物,包括三甲胺(TMA)和三甲胺N-氧化物(TMAO),和肌酐,对这些化合物的体内研究越来越感兴趣。
方法:在本研究中,建立了快速稳定同位素稀释(SID)-UHPLC-MS/MS法同时测定胆碱,左旋肉碱,甜菜碱,TMA,血浆中的TMAO和肌酐,大鼠的肝脏和粪便。该方法使用质量控制(QC)样品在低,中等和高水平。第二,我们应用该方法量化了刺梨果汁(RRTJ)对血浆的影响,肝脏,和粪便中的胆碱含量,左旋肉碱,甜菜碱,TMA,TMAO,高脂饮食诱导的高脂血症大鼠的肌酐,演示该方法的实用性。
结果:检测限(LOD)为0.04-0.027µM,定量限(LOQ)为0.009-0.094µM。血浆中每种代谢物的线性范围为胆碱1.50-96µM;左旋肉碱:2-128µM;甜菜碱:3-192µM;TMA:0.01-40.96µM;TMAO:0.06-61.44µM和肌酐:1-64µM(R2≥0.9954)。肝脏中每种代谢物的线性范围为胆碱:12-768µM;左旋肉碱:1.5-96µM;甜菜碱:10-640µM;TMA:0.5-32µM;TMAO:0.02-81.92µM和肌酐:0.2-204.8µM(R2≥0.9938)。粪便中每种代谢物的线性范围为胆碱:1.5-96µM;L-肉碱:0.01-40.96µM;甜菜碱:1.5-96µM;TMA:1-64µM;TMAO:0.02-81.92µM和肌酸酐:0.02-81.92µM(R2≥0.998)。对于所有分析物,日内和日间变异系数<8%。样品经过多次冻融循环(3次冻融循环)稳定,在室温下24小时,24小时在4°C和20天-80°C样品是稳定的。平均回收率为89%~99%。该方法用于定量高脂血症大鼠的TMAO及其相关代谢产物和肌酐水平。结果表明,高脂饮食导致大鼠TMAO及其相关代谢产物和肌酐的紊乱,经刺梨汁(RRTJ)干预后得到有效改善。
结论:一种测定胆碱的方法,左旋肉碱,甜菜碱,TMA,血浆中的TMAO和肌酐,建立了肝脏和粪便样本,这很简单,节省时间,高精度,准确性和恢复性。
BACKGROUND: Due to the close correlation between choline, L-carnitine, betaine and their intestinal microbial metabolites, including trimethylamine (TMA) and trimethylamine N-oxide (TMAO), and creatinine, there has been an increasing interest in the study of these compounds in vivo.
METHODS: In this study, a rapid stable isotope dilution (SID)-UHPLC-MS/MS method was developed for the simultaneous determination of choline, L-carnitine, betaine, TMA, TMAO and creatinine in plasma, liver and feces of rats. The method was validated using quality control (QC) samples spiked at low, medium and high levels. Second, we applied the method to quantify the effects of Rosa Roxburghii Tratt juice (RRTJ) on plasma, liver, and fecal levels of choline, L-carnitine, betaine, TMA, TMAO, and creatinine in high-fat diet-induced hyperlipidemic rats, demonstrating the utility of the method.
RESULTS: The limits of detection (LOD) were 0.04-0.027 µM and the limits of quantification (LOQ) were 0.009-0.094 µM. The linear ranges for each metabolite in plasma were choline1.50-96 µM; L-carnitine: 2-128 µM; betaine: 3-192 µM; TMA: 0.01-40.96 µM; TMAO: 0.06-61.44 µM and creatinine: 1-64 µM (R2 ≥ 0.9954). The linear ranges for each metabolite in liver were Choline: 12-768 µM; L-carnitine: 1.5-96 µM; betaine: 10-640 µM; TMA: 0.5-32 µM; TMAO: 0.02-81.92 µM and creatinine: 0.2-204.8 µM (R2 ≥ 0.9938). The linear ranges for each metabolite in feces were choline: 1.5-96 µM; L-carnitine: 0.01-40.96 µM; Betaine: 1.5-96 µM; TMA: 1-64 µM; TMAO: 0.02-81.92 µM and Creatinine: 0.02-81.92 µM (R2 ≥ 0.998). The intra-day and inter-day coefficients of variation were < 8 % for all analytes. The samples were stabilized after multiple freeze-thaw cycles (3 freeze-thaw cycles), 24 h at room temperature, 24 h at 4 °C and 20 days at -80 °C. The samples were stable. The average recovery was 89 %-99 %. This method was used to quantify TMAO and its related metabolites and creatinine levels in hyperlipidemic rats. The results showed that high-fat diet led to the disorder of TMAO and its related metabolites and creatinine in rats, which was effectively improved after the intervention of Rosa Roxburghii Tratt juice(RRTJ).
CONCLUSIONS: A method for the determination of choline, L-carnitine, betaine, TMA, TMAO and creatinine in plasma, liver and feces samples was established, which is simple, time-saving, high precision, accuracy and recovery.