The DOI matches its Crossref record; 12 of the 12 references it cites were found in a registry or an index.
Simultaneous Measurement of Serum Tryptophan and Kynurenine by HPLC,
Abstract
l-Tryptophan is an essential amino acid that is required for the biosynthesis of proteins and is the precursor for several important biological compounds, e.g., 5-hydroxytryptamine (serotonin). In an alternative reaction series, the so-called kynurenine pathway, tryptophan is catabolized to form nicotine amides and the vitamin niacin (1) as end products. A cytokine-inducible indoleamine-(2,3)-dioxygenase (IDO) catalyzes the first step of tryptophan degradation (2)(3)(4)(5), forming the intermediate kynurenine. Interferon-γ has been shown to be a potent stimulating cytokine for IDO in vitro (6)(7). Similarly in vivo, a decrease of serum tryptophan and an increase of kynurenine in parallel was described (8)(9)(10)(11)(12), indicating an enhanced cytokine-induced degradation of tryptophan, when the cellular immune system is activated. In particular, the ratio of kynurenine to tryptophan seems to be a sensitive indicator for interferon-γ-induced tryptophan degradation and therefore for an activated immune system (10)(13). Thus, simultaneous measurements of kynurenine and tryptophan, allowing calculation of the ratio, enables indirect examination of endogenous interferon-γ formation.
Overview
The claims and statistics of this paper haven’t been checked yet.
Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.
Integrity signals
Registry
Cites
Statistics
Verification
Claims the paper makes
The claims and statistics of this paper haven’t been checked yet.
Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.
Self-check
Percentages, sums and reported differences re-computed from the paper’s own numbers.
The self-check needs the paper’s full text.
Citations
Cites
Kaur, H., & Halliwell, B. (1994) · FEBS Letters · doi:10.1016/0014-5793(94)00722-5 · Cited by 706
Tryptophan degradation in mice initiated by indoleamine 2,3-dioxygenase.
Takikawa, O., Yoshida, R., Kido, R., & Hayaishi, O. (1986) · Journal of Biological Chemistry · doi:10.1016/s0021-9258(17)35696-x · Cited by 377
Induction of pulmonary indoleamine 2,3-dioxygenase by interferon.
Yoshida, R., Imanishi, J., Oku, T., Kishida, T., & Hayaishi, O. (1981) · Proceedings of the National Academy of Sciences · doi:10.1073/pnas.78.1.129 · Cited by 292
Fuchs, D., Möller, A. A., Reibnegger, G. J., Stöckle, E., Werner, E. R., & WACHTER, H. (1990) · PubMed · Cited by 203
Self-citationCharacteristics of interferon induced tryptophan metabolism in human cells in vitro
Werner-Felmayer, G., Werner, E. R., Fuchs, D., Hausen, A., Reibnegger, G., & Wachter, H. (1989) · Biochimica et Biophysica Acta (BBA) - Molecular Cell Research · doi:10.1016/0167-4889(89)90087-6 · Cited by 190
Self-citationYasui, H., Takai, K., Yoshida, R., & Hayaishi, O. (1986) · Proceedings of the National Academy of Sciences · doi:10.1073/pnas.83.17.6622 · Cited by 190
Human macrophages degrade tryptophan upon induction by interferon-gamma
Werner, E. R., Bitterlich, G., Fuchs, D., Hausen, A., Reibnegger, G., Szabo, G., Dierich, M. P., & Wachter, H. (1987) · Life Sciences · doi:10.1016/0024-3205(87)90149-4 · Cited by 189
Self-citationInduction of Tryptophan Degradation In Vitro and In Vivo : A γ-Interferon-Stimulated Activity
BYRNE, G. I., LEHMANN, L. K., KIRSCHBAUM, J. G., BORDEN, E. C., LEE, C. M., & BROWN, R. R. (1986) · Journal of Interferon Research · doi:10.1089/jir.1986.6.389 · Cited by 183
Werner, E. R., Fuchs, D., Hausen, A., Reibnegger, G. J., & WACHTER, H. (1987) · Clinical Chemistry · doi:10.1093/clinchem/33.11.2028 · Cited by 99
Self-citationTryptophan Degradation in Patients Infected by Human Immunodeficiency Virus
Werner, E. R., FUCHS, D., Hausen, A., Jaeger, H., Reibnegger, G. J., Werner‐Felmayer, G., Dierich, M. P., & Wächter, H. (1988) · Biological Chemistry Hoppe-Seyler · doi:10.1515/bchm3.1988.369.1.337 · Cited by 82
Self-citation
Cited by
Monitoring tryptophan metabolism in chronic immune activation
Schröcksnadel, K., Wirleitner, B., Winkler, C., & Fuchs, D. (2006) · Clinica Chimica Acta · doi:10.1016/j.cca.2005.06.013 · Cited by 551
Self-citationImmunomodulatory effects of Vitamin D in multiple sclerosis
Correale, J., Ysrraelit, M. C., & Gaitan, M. I. (2009) · Brain · doi:10.1093/brain/awp033 · Cited by 538
Interferon-alpha–induced changes in tryptophan metabolism
Capuron, L., Neurauter, G., Musselman, D. L., Lawson, D. H., Nemeroff, C. B., Fuchs, D., & Miller, A. H. (2003) · Biological Psychiatry · doi:10.1016/s0006-3223(03)00173-2 · Cited by 493
Self-citationCapuron, L., Schroecksnadel, S., Féart, C., Aubert, A., Higueret, D., Barberger-Gateau, P., Layé, S., & Fuchs, D. (2011) · Biological Psychiatry · doi:10.1016/j.biopsych.2010.12.006 · Cited by 368
Self-citationProbiotic Supplementation in Patients with Alzheimer’s Dementia - An Explorative Intervention Study
Leblhuber, F., Steiner, K., Schuetz, B., Fuchs, D., & Gostner, J. M. (2018) · Current Alzheimer Research · doi:10.2174/1389200219666180813144834 · Cited by 269
Self-citation
Metadata
- Authors
- Widner, B., Werner, E. R., Schennach, H., Wachter, H., & Fuchs, D.
- Venue
- Clinical Chemistry
- Publisher
- Oxford University Press (OUP)
- Published
- 1997-12-01
- Volume
- 43
- Issue
- 12
- Pages
- 2424-2426
- ISSN
- 0009-9147 (ISSN-L)
- 1530-8561
- OpenAlex
- W1925988920
- Cited by
- 411
- References
- 12
- FWCI
- 2.35
- Type
- journal article
- Language
- en
- Open access
- closed
About these checks
Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.
Statistics and arithmetic are recomputed, not judged.
Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.
What counts as a claim ›How we measure confidence ›How we check this ›
Are you an author, or do you see a problem with this page? Request a review
How to cite
Cite CoChat for the checks on this page, and the paper for its own findings.
- This page
- CoChat. (2026). Citation check: Simultaneous Measurement of Serum Tryptophan and Kynurenine by HPLC,. https://app.cochat.ai/papers/10.1093/clinchem/43.12.2424
- The paper
- Widner, B., Werner, E. R., Schennach, H., Wachter, H., & Fuchs, D. (1997). Simultaneous Measurement of Serum Tryptophan and Kynurenine by HPLC,. Clinical Chemistry. https://doi.org/10.1093/clinchem/43.12.2424
Data sources
Bibliographic data: Semantic Scholar, OpenAlex, Crossref.
Contains information from the Semantic Scholar Academic Graph Datasets, made available under the ODC Attribution License (ODC-BY 1.0).
Semantic Scholar’s data is described in: Kinney, R., et al. (2023). The Semantic Scholar Open Data Platform. arXiv:2301.10140.
