Tryptophan Metabolism in Rat Liver after Administration of Tryptophan, Kynurenine Metabolites, and Kynureninase Inhibitors
Author
Badawy, Abdulla
Bano, Samina
Date
2016-08-11Acceptance date
2016-07-19
Type
Article
Publisher
SAGE
ISSN
1178-6469
Metadata
Show full item recordAbstract
Rat liver tryptophan (Trp), kynurenine pathway metabolites, and enzymes deduced from product/substrate ratios were assessed following acute and/or chronic administration of kynurenic acid (KA), 3-hydroxykynurenine (3-HK), 3-hydroxyanthranilic acid (3-HAA), Trp, and the kynureninase inhibitors benserazide (BSZ) and carbidopa (CBD). KA activated Trp 2,3-dioxygenase (TDO), possibly by increasing liver 3-HAA, but inhibited kynurenine aminotransferase (KAT) and kynureninase activities with 3-HK as substrate. 3-HK inhibited kynureninase activity from 3-HK. 3-HAA stimulated TDO, but inhibited kynureninase activity from K and 3-HK. Trp (50 mg/kg) increased kynurenine metabolite concentrations and KAT from K, and exerted a temporary stimulation of TDO. The kynureninase inhibitors BSZ and CBD also inhibited KAT, but stimulated TDO. BSZ abolished or strongly inhibited the Trp-induced increases in liver Trp and kynurenine metabolites. The potential effects of these changes in conditions of immune activation, schizophrenia, and other disease states are discussed.
Journal/conference proceeding
International Journal of Tryptophan Research;
Citation
Badawy, A.A.B. and Bano, S. (2016) 'Tryptophan metabolism in rat liver after administration of tryptophan, kynurenine metabolites, and kynureninase inhibitors', International Journal of Tryptophan Research, 9, pp.IJTR-S38190. DOI: 10.4137/IJTR.S38190.
Description
Article published in International Journal of Tryptophan Research on 11 August 2016, available open access at: https://doi.org/10.4137/IJTR.S38190.
Sponsorship
Cardiff Metropolitan University (Grant ID: Cardiff Metropolian (Internal))
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