Development and validation of a single analytical method for the determination of tryptophan, and its kynurenine metabolites in rat plasma

Möller, Marisa; Preez, Jan L. du; Harvey, Brian H.

doi:10.1016/j.jchromb.2012.04.030

Cited by 65 publications

(64 citation statements)

References 23 publications

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“…The analysis was performed using a 100 × 2.1-mm Restek C18 Aqueous column (Restek, Pennsylvania, USA). The LC-MS detection parameters and mobile phases were prepared as previously described [19]. …”

Section: Methodsmentioning

confidence: 99%

Activation of brain indoleamine 2,3-dioxygenase contributes to epilepsy-associated depressive-like behavior in rats with chronic temporal lobe epilepsy

Xie

Cai

et al. 2014

Journal of Neuroinflammation

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BackgroundDepression has most often been diagnosed in patients with temporal lobe epilepsy (TLE), but the mechanism underlying this association remains unclear. In this study, we report that indoleamine 2,3-dioxygenase 1 (IDO1), a rate-limiting enzyme in tryptophan metabolism, plays a key role in epilepsy-associated depressive-like behavior.MethodsRats which develop chronic epilepsy following pilocarpine status epilepticus exhibited a set of interictal disorders consistent with depressive-like behavior. Changes of depressive behavior were examined by taste preference test and forced swim test; brain IL-1β, IL-6 and IDO1 expression were quantified using real-time reverse transcriptase PCR; brain kynurenine/tryptophan and serotonin/tryptophan ratios were analyzed by liquid chromatography-mass spectrometry. Oral gavage of minocycline or subcutaneous injection of 1-methyltryptophan (1-MT) were used to inhibite IDO1 expression.ResultsWe observed the induction of IL-1β and IL-6 expression in rats with chronic TLE, which further induced the upregulation of IDO1 expression in the hippocampus. The upregulation of IDO1 subsequently increased the kynurenine/tryptophan ratio and decreased the serotonin/tryptophan ratio in the hippocampus, which contributed to epilepsy-associated depressive-like behavior. The blockade of IDO1 activation prevented the development of depressive-like behavior but failed to influence spontaneous seizures. This effect was achieved either indirectly, through the anti-inflammatory tetracycline derivative minocycline, or directly, through the IDO antagonist 1-MT, which normalizes kynurenine/tryptophan and serotonin/tryptophan ratios.ConclusionBrain IDO1 activity plays a key role in epileptic rats with epilepsy-associated depressive-like behavior.

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Section: Methodsmentioning

confidence: 99%

Activation of brain indoleamine 2,3-dioxygenase contributes to epilepsy-associated depressive-like behavior in rats with chronic temporal lobe epilepsy

Xie

Cai

et al. 2014

Journal of Neuroinflammation

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“…Charcoal stripped human plasma was prepared according to a previous paper [19]; that is, 20 ml of plasma was added with 1.2 g of charcoal activated powder (Fisher Scientific) and rotated for 2 h, then centrifuged at 14,000 g for 10 min to obtain the supernatant. The ‘stripped’ human plasma was confirmed by LC–MS/MS to be free of Trp and Kyn.…”

Section: Methodsmentioning

confidence: 99%

“…However, HPLC UV detection usually lacks selectivity and has a relatively long run time. In recent years, LC–MS/MS methods have also been reported for analyzing Trp and Kyn in plasma samples [15–19], however, the detailed assay validations are not provided.…”

mentioning

confidence: 99%

A Simple LC–MS/MS Method for Determination of Kynurenine and Tryptophan Concentrations in Human Plasma from Hiv-Infected Patients

et al. 2013

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Background Indoleamine 2,3-dioxygenase, catalyzing tryptophan (Trp) metabolism through the kynurenine (Kyn) metabolic pathway, plays important roles in immune suppression and the CNS. In this article, we report a simple, rapid and specific LC–MS/MS method for accurate determination of Kyn and Trp concentrations in human plasma from HIV-infected patients. Results The human plasma sample (100 μl) was mixed with Kyn-d4 and Trp-d5 internal standards and then precipitated with trifluoroacetic acid. The supernatant was directly analyzed by LC–MS/MS. The assay using surrogate matrix calibrators was validated for precision, accuracy, matrix effect, extraction efficiency and stability. Some assay validation issues for endogenous substance bioanalysis using an LC–MS/MS method are discussed. Conclusion A simple, specific and reproducible LC–MS/MS method has been developed and validated for measuring Kyn and Trp in human plasma samples.

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“…Several groups have established the value of analytical systems based on mass spectrometry for components of the kynurenine pathway which represents the main route for the oxidation of tryptophan (Marcos et al., 2016, Galba et al., 2016, Orsatti et al., 2015, Schwieler et al., 2015, Savitz et al., 2015, Zhang et al., 2015, Meinitzer et al., 2014, Lesniak et al., 2013, Zheng et al., 2012, Moller et al., 2012, Wilson et al., 2012, Notarangelo et al., 2012, Owe-Young et al., 2008, Amirkhani et al., 2002, Boni et al., 1994, Smythe et al., 2002, Kita et al., 2002, Saito et al., 1993). These systems have been applied to the measurement of individual kynurenines in blood, plasma or cerebrospinal fluid as well as components of the kynurenine pathway within brain tissue.…”

Section: Methodsmentioning

confidence: 99%

Kynurenine pathway metabolism following prenatal KMO inhibition and in Mecp2+/− mice, using liquid chromatography-tandem mass spectrometry

Forrest

Kennedy

Rodgers

et al. 2016

Neurochemistry International

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To quantify the full range of tryptophan metabolites along the kynurenine pathway, a liquid chromatography – tandem mass spectrometry method was developed and used to analyse brain extracts of rodents treated with the kynurenine-3-mono-oxygenase (KMO) inhibitor Ro61-8048 during pregnancy. There were significant increases in the levels of kynurenine, kynurenic acid, anthranilic acid and 3-hydroxy-kynurenine (3-HK) in the maternal brain after 5 h but not 24 h, while the embryos exhibited high levels of kynurenine, kynurenic acid and anthranilic acid after 5 h which were maintained at 24 h post-treatment. At 24 h there was also a strong trend to an increase in quinolinic acid levels (P = 0.055). No significant changes were observed in any of the other kynurenine metabolites. The results confirm the marked increase in the accumulation of some neuroactive kynurenines when KMO is inhibited, and re-emphasise the potential importance of changes in anthranilic acid. The prolonged duration of metabolite accumulation in the embryo brains indicates a trapping of compounds within the embryonic CNS independently of maternal levels. When brains were examined from young mice heterozygous for the meCP2 gene – a potential model for Rett syndrome - no differences were noted from control mice, suggesting that the proposed roles for kynurenines in autism spectrum disorder are not relevant to Rett syndrome, supporting its recognition as a distinct, independent, condition.

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Development and validation of a single analytical method for the determination of tryptophan, and its kynurenine metabolites in rat plasma

Cited by 65 publications

References 23 publications

Activation of brain indoleamine 2,3-dioxygenase contributes to epilepsy-associated depressive-like behavior in rats with chronic temporal lobe epilepsy

Activation of brain indoleamine 2,3-dioxygenase contributes to epilepsy-associated depressive-like behavior in rats with chronic temporal lobe epilepsy

A Simple LC–MS/MS Method for Determination of Kynurenine and Tryptophan Concentrations in Human Plasma from Hiv-Infected Patients

Kynurenine pathway metabolism following prenatal KMO inhibition and in Mecp2+/− mice, using liquid chromatography-tandem mass spectrometry

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