Li Ma1, Biao Xu, Wenjuan Wang, Wenping Deng, Min Ding. 1. Key Laboratory of Clinical Laboratory Diagnostics, Ministry of Education, The Faculty of Laboratory Medicine, Chongqing Medical University, Chongqing, 400016, China.
Abstract
BACKGROUND: In order to understand the tryptophan catabolism in acute and chronic hepatitis B patients, we quantitatively analyzed plasma kynurenine and tryptophan simultaneously by high performance liquid chromatography with programmed wavelength ultraviolet detection. METHODS: A new and specific high performance liquid chromatography method to simultaneously measure plasma kynurenine and tryptophan with programmed wavelength ultraviolet detection using 3-nitro-tyrosine as internal standard was elaborated. Thirty patients were recruited (10 patients with acute HBV, 10 with chronic HBV and 10 healthy subjects). RESULTS: The retention times of kynurenine and tryptophan were 2.9 min and 4.4 min, respectively. For kynurenine, the assay was linear from 0.442 micromol/l to 18.3 micromol/l. For tryptophan, the linearity was from 3.67 to 470 micromol/l. The detection limits were 0.014 micromol/l for Kyn and 0.122 micromol/l for Trp, respectively. Its precision and recovery are satisfactory. In this study we found that the kynurenine per tryptophan ratio of acute group is higher than control group and chronic group. CONCLUSIONS: The method is simple, fast, accurate, and suitable for applicability to clinical measurement.
BACKGROUND: In order to understand the tryptophan catabolism in acute and chronic hepatitis Bpatients, we quantitatively analyzed plasma kynurenine and tryptophan simultaneously by high performance liquid chromatography with programmed wavelength ultraviolet detection. METHODS: A new and specific high performance liquid chromatography method to simultaneously measure plasma kynurenine and tryptophan with programmed wavelength ultraviolet detection using 3-nitro-tyrosine as internal standard was elaborated. Thirty patients were recruited (10 patients with acute HBV, 10 with chronic HBV and 10 healthy subjects). RESULTS: The retention times of kynurenine and tryptophan were 2.9 min and 4.4 min, respectively. For kynurenine, the assay was linear from 0.442 micromol/l to 18.3 micromol/l. For tryptophan, the linearity was from 3.67 to 470 micromol/l. The detection limits were 0.014 micromol/l for Kyn and 0.122 micromol/l for Trp, respectively. Its precision and recovery are satisfactory. In this study we found that the kynurenine per tryptophan ratio of acute group is higher than control group and chronic group. CONCLUSIONS: The method is simple, fast, accurate, and suitable for applicability to clinical measurement.
Authors: Lijie Zhai; Erik Ladomersky; April Bell; Corey Dussold; Krislyn Cardoza; Jun Qian; Kristen L Lauing; Derek A Wainwright Journal: Methods Enzymol Date: 2019-07-24 Impact factor: 1.600