Determination of tryptophan and its metabolites in human plasma and serum by high-performance liquid chromatography with automated sample clean-up system.
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.
Morita
I
I
Institute of Pharmaceutical Sciences, Hiroshima University School of Medicine, Japan.
Kawamoto
M
M
Hattori
M
M
Eguchi
K
K
Sekiba
K
K
Yoshida
H
H
D001322:Autoanalysis; D002851:Chromatography, High Pressure Liquid; D005215:Fasting / Q000097:blood; D006801:Humans; D010949:Plasma / Q000032:analysis; D014364:Tryptophan / Q000097:blood* / Q000378:metabolism
D014364:Tryptophan