The First Clinical Medical School of Guangzhou University of Chinese Medicine, Guangzhou 510000, China; Chongqing Hospital of The First Affiliated Hospital of Guangzhou University of Chinese Medicine (Chongqing Beibei District Traditional Chinese Medicine Hospital), Chongqing 400000, China.
The First Clinical Medical School of Guangzhou University of Chinese Medicine, Guangzhou 510000, China; Department of Pathology, Fudan Cancer Hospital, Guangzhou 510000, China.
J Pharm Biomed Anal. 2024 Dec 15;251:116426. doi: 10.1016/j.jpba.2024.116426. Epub 2024 Aug 15.
Background and Aims Abnormalities in tryptophan (TRP) metabolism induce abdominal pain and intestinal motility disorders. The study of TRP metabolism in diarrhea-predominant-irritable bowel syndrome (IBS-D) is important for the prevention, diagnosis, and treatment of this disease. In this study, a rapid and reliable ultra performance liquid chromatography-mass spectrometry (UPLC-MS) method was established to quantify tryptophan-kynurenine (TRP-Kyn) metabolism in the colon of a rat model with IBS-D. Methods The proteins were precipitated by methanol, chromatographically separated on a Welch Ultimate® Polar RP column with a gradient elution for 12 min, and detected by high-resolution tandem mass spectrometry. Pure water were used as an alternative mechanism for standard calibration, and the stable structural analog 2-Cl-Phe was used as an internal standard. Results Within a certain range, the r of TRP, kynurenine (Kyn) and quinolinic acid (QA), kynurenic acid (KA) are greater than 0.99, were found to be accurate and precise. The metabolism of TRP was significantly up-regulated along the Kyn pathway in the IBS-D model rats and normalized after treatment with pivacurium bromide. Conclusion This study investigates the mechanisms of IBS-D gastrointestinal dysfunction from the perspective of colonic TRP metabolism, and also provides new directions for the diagnosis and therapeutic approach of this disease.
色氨酸（TRP）代谢异常可引起腹痛和肠道运动障碍。研究腹泻型肠易激综合征（IBS-D）中的 TRP 代谢对于预防、诊断和治疗这种疾病非常重要。在这项研究中，建立了一种快速可靠的超高效液相色谱-质谱（UPLC-MS）方法，用于定量 IBS-D 大鼠模型结肠中色氨酸-犬尿氨酸（TRP-Kyn）代谢。
用甲醇沉淀蛋白质，在 Welch Ultimate® Polar RP 柱上进行色谱分离，梯度洗脱 12 分钟，并用高分辨串联质谱检测。纯水被用作标准校准的替代机制，稳定结构类似物 2-Cl-Phe 被用作内标。
在一定范围内，TRP、犬尿氨酸（Kyn）和喹啉酸（QA）、犬尿氨酸（KA）的 r 均大于 0.99，结果准确且精密。在 IBS-D 模型大鼠中，TRP 沿着 Kyn 途径的代谢显著上调，经溴匹立明治疗后恢复正常。
本研究从结肠 TRP 代谢的角度探讨了 IBS-D 胃肠功能障碍的机制，为该疾病的诊断和治疗方法提供了新的方向。
