Publication
Title
Relationships between lower plasma L-tryptophan levels and immune-inflammatory variables in depression
Author
Abstract
Despite much research, the pathophysiology underlying lower L-tryptophan (L-TRP) availability in major depression has remained elusive. The present study investigates whether lower L-TRP availability in major depression is related to immune activation which may occur in that illness and is known to modulate L-TRP metabolism. Toward this end, the authors have measured the following in depressed patients and normal control subjects: plasma levels of L-TRP, and the competing amino acids (CAA) valine, leucine, isoleucine, tyrosine, and phenylalanine, together with indices of immune function such as haptoglobin (Hp) and transferrin (Tf) plasma levels, dipeptidyl peptidase IV (DPP IV) serum activity, and mitogen-induced culture supernatant interleukin-6 (Il6) production. Both plasma levels of L-TRP and the L-TRP/CAA ratio were significantly lower in major depressed subjects as compared with healthy control subjects. There were significant correlations between plasma L-TRP levels, on the one hand, and Tf plasma levels, DPP IV activity (both positive), Il-6 production, and Hp plasma levels (both negative), on the other. Up to 63.7% of the variance in L-TRP plasma concentrations could be explained by DPP IV, Hp, Il-6 values; and gender. Up to 50% of the variance in the L-TRP/CAA ratio could be explained by Hp values (negative correlation) and gender. It is hypothesized that lower plasma L-TRP availability in major depression may be related to the immune response in that illness.
Language
English
Source (journal)
Psychiatry research. - Amsterdam
Publication
Amsterdam : 1993
ISSN
0165-1781
Volume/pages
49:2(1993), p. 151-165
ISI
A1993MX09000005
Full text (Publisher's DOI)
Full text (publisher's version - intranet only)
UAntwerpen
Faculty/Department
Research group
Publication type
Subject
Affiliation
Publications with a UAntwerp address
External links
Web of Science
Record
Identification
Creation 19.07.2012
Last edited 02.12.2017
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