Author(s)

Hiroi Tomioka^1,2, Junichi Masuda³, Akikazu Takada⁴, Akira Iwanami¹

¹Department of Psychiatry, Showa University School of Medicine, Tokyo, Japan.
²Department of Psychiatry, Showa University Northern Yokohama Hospital, Yokohama, Japan.
³Global Application Development Center, Shimadzu Corporation, Kanagawa-ken, Japan.
⁴International Projects on Food and Health (NPO), Tokyo, Japan.

Background: It is not well analyzed whether there are differences in plasma levels of tryptophan (TRP) metabolites between healthy control people (HC) and patients of type II bipolar depression (BDII). Methods: Ultra high-speed liquid chromatography/mass spectrometry has been used for the simultaneous determination of plasma levels of tryptophan metabolites in depressive patients. Results: Plasma levels of TRP are not different between HC and patients of BDII. Serotonin (5-HT) levels are higher in BDII than HC. Plasma levels of 5-HIAA of HC are higher than those of old women of BDII, but lower in young women of BDII. Plasma levels of kynurenine (KYN) of HC are not different from those of patients of BDII. Conclusion: Plasma levels of 5-HT are higher in patients of BDII than those of HC, which may suggest that use of drugs inhibiting the 5-HT transportation and lower transporter biding may increase plasma levels of 5-HT in patients of BD.

Depression, Monopolar Depression, Bipolar Depression, Tryptophan, Serotonin, 5-Hydroxyindole Acetic Acid, Kynurenine, SSRI (Selective Serotonin Reuptake Inhibitor), SNRI (Serotonin Norepinephrine Reuptake Inhibitor), Anxiolytic, Antipsychotic

Tomioka, H. , Masuda, J. , Takada, A. and Iwanami, A. (2020) Comparison of Plasma Levels of Tryptophan Metabolites between Healthy People and Patients of Bipolar Depression at Various Age and Gender. Journal of Biomedical Science and Engineering, 13, 120-129. doi: 10.4236/jbise.2020.136012.