The DOI matches its Crossref record; 33 of the 33 references it cites were found in a registry or an index.
Antioxidant activities of some tryptophan metabolites: possible implication for inflammatory diseases.
Open accessAbstract
The antioxidant properties of tryptophan and some of its oxidative metabolites were examined by measuring how efficiently they inhibited peroxyl radical-mediated oxidation of phosphatidylcholine liposomes and B-phycoerythrin. Low micromolar concentrations of 5-hydroxytryptophan, 3-hydroxykynurenine, xanthurenic acid, or 3-hydroxyanthranilic acid, but not their corresponding nonhydroxylated metabolic precursors, scavenged peroxyl radicals with high efficiency. In particular, 3-hydroxykynurenine and 3-hydroxyanthranilic acid protected B-phycoerythrin from peroxyl radical-mediated oxidative damage more effectively than equimolar amounts of either ascorbate or Trolox (a water-soluble analog of vitamin E). Enzyme activities involved or related to oxidative tryptophan metabolism, as well as endogenous concentrations of tryptophan and its metabolites, were determined within tissues of mice suffering from acute viral pneumonia. Infection resulted in a 100-fold induction of pulmonary indoleamine 2,3-dioxygenase (EC 1.13.11.17) as reported [Yoshida, R., Urade, Y., Tokuda, M. & Hayaishi, O. (1979) Proc. Natl. Acad. Sci. USA 76, 4084-4086]. This was accompanied by a 16- and 3-fold increase in the levels of lung kynurenine and 3-hydroxykynurenine, respectively. In contrast, endogenous concentrations of tryptophan and xanthurenic acid did not increase and 3-hydroxyanthranilic acid could not be detected. The activity of the superoxide anion (O2-.)-producing enzyme xanthine oxidase increased 3.5-fold during infection while that of the O2-.-removing superoxide dismutase decreased to 50% of control levels. These results plus the known requirement of indoleamine 2,3-dioxygenase for superoxide anion for catalytic activity suggest that viral pneumonia is accompanied by oxidative stress and that induction of indoleamine 2,3-dioxygenase may represent a local antioxidant defence against this and possibly other types of inflammatory diseases.
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Cites
Tissue Destruction by Neutrophils
Epstein, F. H., & Weiss, S. J. (1989) · New England Journal of Medicine · doi:10.1056/nejm198902093200606 · Cited by 3,950
Bilirubin Is an Antioxidant of Possible Physiological Importance
Stocker, R., Yamamoto, Y., McDonagh, A. F., Glazer, A. N., & Ames, B. N. (1987) · Science · doi:10.1126/science.3029864 · Cited by 2,948
Self-citationAmes, B. N., Cathcart, R., Schwiers, E., & Hochstein, P. (1981) · Proceedings of the National Academy of Sciences · doi:10.1073/pnas.78.11.6858 · Cited by 2,909
Nathan, C. F., Murray, H. W., Wiebe, M. E., & Rubin, B. Y. (1983) · The Journal of experimental medicine · doi:10.1084/jem.158.3.670 · Cited by 1,962
Antioxidant defenses and lipid peroxidation in human blood plasma.
Frei, B., Stocker, R., & Ames, B. N. (1988) · Proceedings of the National Academy of Sciences · doi:10.1073/pnas.85.24.9748 · Cited by 1,252
Self-citationOxidants and human disease: some new concepts 1
Halliwell, B. (1987) · The FASEB Journal · doi:10.1096/fasebj.1.5.2824268 · Cited by 1,203
Antioxidant activity of albumin-bound bilirubin.
Stocker, R., Glazer, A. N., & Ames, B. N. (1987) · Proceedings of the National Academy of Sciences · doi:10.1073/pnas.84.16.5918 · Cited by 766
Self-citationCorte, E. D., & Stirpe, F. (1972) · Biochemical Journal · doi:10.1042/bj1260739 · Cited by 436
[61] Assay of superoxide dismutase activity in tumor tissue
Oberley, L. W., & Spitz, D. R. (1984) · Methods in Enzymology · doi:10.1016/s0076-6879(84)05064-3 · Cited by 420
Oxygen Radicals in Influenza-Induced Pathogenesis and Treatment with Pyran Polymer-Conjugated SOD
Oda, T., Akaike, T., Hamamoto, T., Suzuki, F., Hirano, T., & Maeda, H. (1989) · Science · doi:10.1126/science.2543070 · Cited by 418
Cited by
Kynurenines in the mammalian brain: when physiology meets pathology
Schwarcz, R., Bruno, J. P., Muchowski, P. J., & Wu, H.-Q. (2012) · Nature Reviews Neuroscience · doi:10.1038/nrn3257 · Cited by 1,530
Maes, M., Galecki, P., Chang, Y. S., & Berk, M. (2011) · Progress in Neuro-Psychopharmacology and Biological Psychiatry · doi:10.1016/j.pnpbp.2010.05.004 · Cited by 1,140
Maes, M., Leonard, B. E., Myint, A. M., Kubera, M., & Verkerk, R. (2011) · Progress in Neuro-Psychopharmacology and Biological Psychiatry · doi:10.1016/j.pnpbp.2010.12.017 · Cited by 700
Kynurenine Pathway Metabolites in Humans: Disease and Healthy States
Chen, Y., & Guillemin, G. J. (2009) · International Journal of Tryptophan Research · doi:10.4137/ijtr.s2097 · Cited by 628
Tryptophan metabolism, from nutrition to potential therapeutic applications
Le Floc’h, N., Otten, W., & Merlot, E. (2011) · Amino Acids · doi:10.1007/s00726-010-0752-7 · Cited by 561
Metadata
- Authors
- Christen, S., Peterhans, E., & Stocker, R.
- Venue
- Proceedings of the National Academy of Sciences
- Published
- 1990-04
- Volume
- 87
- Issue
- 7
- Pages
- 2506-2510
- ISSN
- 0027-8424 (ISSN-L)
- 1091-6490
- OpenAlex
- W2072165349
- Cited by
- 334
- References
- 33
- FWCI
- 3.32
- Type
- journal article
- Language
- en
- Open access
- green
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