Establishment of a UPLC-MS method for quantitative analysis of tryptophan-kynurenine metabolism in IBS-D model rats

• Published in: Journal of pharmaceutical and biomedical analysis 2024-12, Vol.251, p.116426, Article 116426
• Main Authors: Lu, Qin, Yang, Huifei, Feng, Siqi, Xie, Xiangyu, Liu, Shan, Zhu, He, Su, Zhiqiang, Zhou, Yingchun, Tang, Hongmei
• Format: Article
• Language: English
• Subjects: Diarrhea predominant-irritable bowel syndrome; Tryptophan-kynurenine metabolic; Ultra High-performance Liquid Chromatography- Mass Spectrometry
• ISSN: 0731-7085; 1873-264X; 1873-264X
• DOI: 10.1016/j.jpba.2024.116426

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. •To develop an UPLC-MS method to quantify kynurenine metabolism in the colon of IBS-D model rats.•Regulation of tryptophan metabolism by inhibiting IDO1 expression may alleviate visceral hypersensitivity.•IDO has the potential to be a biomarker for IBS-D.