Amino Acids

, Volume 41, Issue 5, pp 1195–1205

Tryptophan metabolism, from nutrition to potential therapeutic applications

Authors

    • INRA, UMR1079, Système d’ElevageNutrition Animale et Humaine (SENAH)
    • Agrocampus OuestUMR1079 SENAH
  • Winfried Otten
    • Research Unit Behavioural PhysiologyLeibniz Institute for Farm Animal Biology
  • Elodie Merlot
    • INRA, UMR1079, Système d’ElevageNutrition Animale et Humaine (SENAH)
    • Agrocampus OuestUMR1079 SENAH
Invited Review

DOI: 10.1007/s00726-010-0752-7

Cite this article as:
Le Floc’h, N., Otten, W. & Merlot, E. Amino Acids (2011) 41: 1195. doi:10.1007/s00726-010-0752-7

Abstract

Tryptophan is an indispensable amino acid that should to be supplied by dietary protein. Apart from its incorporation into body proteins, tryptophan is the precursor for serotonin, an important neuromediator, and for kynurenine, an intermediary metabolite of a complex metabolic pathway ending with niacin, CO2, and kynurenic and xanthurenic acids. Tryptophan metabolism within different tissues is associated with numerous physiological functions. The liver regulates tryptophan homeostasis through degrading tryptophan in excess. Tryptophan degradation into kynurenine by immune cells plays a crucial role in the regulation of immune response during infections, inflammations and pregnancy. Serotonin is synthesized from tryptophan in the gut and also in the brain, where tryptophan availability is known to influence the sensitivity to mood disorders. In the present review, we discuss the major functions of tryptophan and its role in the regulation of growth, mood, behavior and immune responses with regard to the low availability of this amino acid and the competition between tissues and metabolic pathways for tryptophan utilization.

Keywords

TryptophanMetabolismNutritionImmune responseMood disorders

Copyright information

© Springer-Verlag 2010