Clinical Application of Determination of Tryptophan and Its Metabolites

Tryptophan is an indispensable amino acid that should 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 kynurenic and xanthurenic acids.Tryptophan metabolism within different tissues is associated with numerous physiological functions.The occurrence and development of a variety of clinical diseases are closely related to tryptophan metabolism disorder.Therefore,the determination of main tryptophan metabolites can provide the evidence for the diagnosis,treatment,monitoring,and occurrence mechanism research of the related diseases.The article briefly summarizes the metabolism,physiological functions,determination and clinical application of tryptophan.