TITLE:
Effects of Gender, Age, and Clot Formation on the Measurements of Tryptophan Metabolites in Blood
AUTHORS:
Junichi Masuda, Masato Karayama, Takafumi Suda, Masato Maekawa, Fumiko Shimizu, Akikazu Takada
KEYWORDS:
Plasma, Serum, Platelet, Tryptophan, Serotonin, 5-Hydroxyindole Acetic Acid, Kynurenine, 3-Hydroxykynurenine, Kynurenic Acid, Anthranilic Acid, Xanthurenic Acid, Indole-3-Acetic Acid
JOURNAL NAME:
Food and Nutrition Sciences,
Vol.10 No.7,
July
29,
2019
ABSTRACT: Background: Tryptophan metabolism plays important roles in health and diseases.
Although simultaneous measurements of tryptophan metabolites are successfully
measured, influences of age, gender, and clot formation on the measurements
have not been reported. Methods: We took blood from young and old
Japanese men and women and compared plasma levels of tryptophan metabolites. We
also took plasma and serum from the blood of middle-aged men (n = 10).
Metabolites analysis was performed by a liquid chromatograph tandem mass spectrometer, the LCMS-8060 quadrupole mass spectrometer combined
with Nexera X2 liquid chromatograph system
(Shimadzu Corporation, Kyoto, Japan). Body mass index (BMI) and TRP metabolites
have been measured in healthy young men (n = 48), young women (n = 47), old men
(n = 44), and old women (n = 39). TRP metabolites were measured by using the
ultrahigh speed liquid chromatography-mass spectroscopy (Shimadzu Corporation). Results: Tryptophan and its metabolites such as serotonin, 5-hydroxyindole acetic acid, indole-3-acetic acid, kynurenine,
anthranilic acid, were higher in young women and old men than young men and old
women. Plasma levels of 3-hydroxykynurenine and xanthurenic acid were lower in
young women and old men. Comparison of plasma and serum indicates that most of metabolites were higher in serum than plasma
except for 3-hydroxy-kynurenine
and quinolinic acid. Conclusion: Metabolites of the upper stream of
degradation of tryptophan were higher in young women and old men than young men
and old women, which suggests that
the degradation of tryptophan was accelerated in young men and old women than
young women and old men. Serum preparation may activate tryptophan degradation
resulting in higher levels of metabolites in serum than in plasma.