Department of Psychiatry and Psychotherapy, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, J5, 68159, Mannheim, Germany.
Department of Experimental and Clinical Pharmacology, Medical University of Lublin, Jaczewskiego 8b, 20-090, Lublin, Poland.
Sci Rep. 2023 Aug 2;13(1):12554. doi: 10.1038/s41598-023-39774-3.
Tryptophan breakdown metabolites formed along the kynurenine pathway play a significant role in pregnancy and fetal development. To understand their involvement, it is crucial to quantify the levels of tryptophan (TRP), kynurenine (KYN), and kynurenic acid (KYNA) in relevant biological samples such as the placenta, fetal membranes, and umbilical cord. This study used liquid chromatography-tandem mass spectrometry (LC-MS/MS) to determine TRP, KYN, and KYNA levels. The LC-MS/MS method was optimized for high sensitivity and specificity, demonstrating good reproducibility with a precision of < 10% CV and an accuracy of 85-115%. The lower limit of quantification for both TRP and KYN was 0.5 µg/ml, while for KYNA, it was 0.5 ng/mL. The method exhibited linearity within the examined range of concentrations in the homogenate, ranging from 0.5 to 30 µg/ml for TRP and KYN and from 0.5 to 25 ng/ml for KYNA. Using this method, we found significant differences in the concentrations of these substances in investigated maternal-fetal compartments. Placenta samples exhibited higher KYN and lower KYNA concentrations than the umbilical cord and fetal membrane, indicating a potentially important role for kynurenines in late pregnancy. Collectively, this finding may facilitate further research and provide inside into the involvement of the kynurenine pathway of TRP metabolism in fetal development.
色氨酸分解代谢产物沿犬尿氨酸途径形成，在妊娠和胎儿发育中发挥重要作用。为了了解它们的参与，关键是要定量测定胎盘、胎膜和脐带等相关生物样本中的色氨酸（TRP）、犬尿氨酸（KYN）和犬尿喹啉酸（KYNA）水平。本研究使用液相色谱-串联质谱（LC-MS/MS）来确定 TRP、KYN 和 KYNA 水平。LC-MS/MS 方法进行了优化，以实现高灵敏度和特异性，具有良好的重现性，精密度<10%CV，准确度为 85-115%。TRP 和 KYN 的定量下限均为 0.5 µg/ml，而 KYNA 的定量下限为 0.5 ng/ml。该方法在匀浆中检测到的浓度范围内表现出线性关系，TRP 和 KYN 的浓度范围为 0.5 至 30 µg/ml，KYNA 的浓度范围为 0.5 至 25 ng/ml。使用该方法，我们发现这些物质在研究的母胎隔室中的浓度存在显著差异。胎盘样本的 KYN 浓度较高，KYNA 浓度较低，与脐带和胎膜相比，表明犬尿氨酸在晚期妊娠中可能具有重要作用。总的来说，这一发现可能有助于进一步的研究，并提供色氨酸代谢犬尿氨酸途径在胎儿发育中的参与情况的内部信息。
