title: Determination of tryptophan and its metabolites in human plasma and serum by high-performance liquid chromatography with automated sample clean-up system.
abstract: An automated high-performance liquid chromatographic method that incorporates direct injection of biological samples followed by chromatographic sample clean-up in a precolumn is described for the determination of tryptophan and its metabolites in human plasma and serum. The system gave reproducible data with a coefficient of variation of less than 3% with a sample size of 100 microliters of human plasma. The major tryptophan metabolites found in 100 microliters of human plasma were kynurenine, indolelactic acid, indoleacetic acid, indolepropionic acid, serotonin and 5-hydroxyindoleacetic acid. The level of tryptophan and kynurenine in individuals was constant in comparison with other metabolites. Analysis of samples from normal controls, diabetics, gravida and their foetuses showed a tendency for tryptophan metabolites to be low in maternal plasma.
authors.affiliation: Institute of Pharmaceutical Sciences, Hiroshima University School of Medicine, Japan.
authors.forename: I
authors.initials: I
authors.lastname: Morita
authors.forename: M
authors.initials: M
authors.lastname: Kawamoto
authors.forename: M
authors.initials: M
authors.lastname: Hattori
authors.forename: K
authors.initials: K
authors.lastname: Eguchi
authors.forename: K
authors.initials: K
authors.lastname: Sekiba
authors.forename: H
authors.initials: H
authors.lastname: Yoshida
mesh_terms: D001322:Autoanalysis; D002851:Chromatography, High Pressure Liquid; D005215:Fasting / Q000097:blood; D006801:Humans; D010949:Plasma / Q000032:analysis; D014364:Tryptophan / Q000097:blood* / Q000378:metabolism
chemical_list: D014364:Tryptophan