Considerable evidence points towards a prominent role for central nervous system (CNS) mechanisms in the pathogenesis of chronic fatigue syndrome (CFS), a disorder characterized chiefly by persistent, often debilitating, fatigue. We wished to characterize circulating profiles of putative amino acid modulators of CNS 5-hydroxytryptamine (5-HT; serotoninergic) and dopaminergic function in CFS patients at rest, as well as during symptom-limited exercise and subsequent recovery. Groups of 12 CFS patients and 11 age- and sex-matched sedentary controls, with similar physical activity histories, underwent ramp-incremental exercise to the limit of tolerance. Plasma amino acid concentrations, oxygen uptake and ratings of perceived exertion were measured at rest, and during exercise and recovery. Peak oxygen uptake was significantly lower in the CFS patients compared with controls. Rating of perceived exertion in the patients was higher at all time points measured, including at rest, relative to controls. Levels of free tryptophan (free Trp), the rate-limiting 5-HT precursor, were significantly higher in CFS patients at exhaustion and during recovery, whereas concentrations of branched-chain amino acids (BCAA) and large neutral amino acids (LNAA) were lower in CFS patients at exhaustion, and for LNAA also during recovery. Consequently, the [free Trp]/[BCAA] and [free Trp]/[LNAA] ratios were significantly higher in CFS patients, except at rest. On the other hand, levels of tyrosine, the rate-limiting dopaminergic precursor, were significantly lower at all time points in the CFS patients. The significant differences observed in a number of key putative CNS 5-HT and dopaminergic modulators, coupled with the exacerbated perception of effort, provide further evidence for a potentially significant role for CNS mechanisms in the pathogenesis of CFS.
Skip Nav Destination
Article navigation
August 2003
-
Cover Image
Cover Image
- PDF Icon PDF LinkTable of Contents
Research Article|
August 01 2003
Chronic fatigue syndrome: new evidence for a central fatigue disorder
Evelina GEORGIADES;
Evelina GEORGIADES
*Centre for Exercise Science and Medicine, Institute of Biomedical & Life Sciences, University of Glasgow, Glasgow G12 8QQ, Scotland, U.K.
Search for other works by this author on:
Wilhelmina M. H. BEHAN;
Wilhelmina M. H. BEHAN
†Department of Pathology, University of Glasgow, Glasgow G12 8QQ, Scotland, U.K.
Search for other works by this author on:
Liam P. KILDUFF;
Liam P. KILDUFF
*Centre for Exercise Science and Medicine, Institute of Biomedical & Life Sciences, University of Glasgow, Glasgow G12 8QQ, Scotland, U.K.
Search for other works by this author on:
Marios HADJICHARALAMBOUS;
Marios HADJICHARALAMBOUS
*Centre for Exercise Science and Medicine, Institute of Biomedical & Life Sciences, University of Glasgow, Glasgow G12 8QQ, Scotland, U.K.
Search for other works by this author on:
Eileen E. MACKIE;
Eileen E. MACKIE
‡Department of Medicine and Therapeutics, University of Glasgow, Glasgow G12 8QQ, Scotland, U.K.
Search for other works by this author on:
John WILSON;
John WILSON
*Centre for Exercise Science and Medicine, Institute of Biomedical & Life Sciences, University of Glasgow, Glasgow G12 8QQ, Scotland, U.K.
Search for other works by this author on:
Susan A. WARD;
Susan A. WARD
*Centre for Exercise Science and Medicine, Institute of Biomedical & Life Sciences, University of Glasgow, Glasgow G12 8QQ, Scotland, U.K.
Search for other works by this author on:
Yannis P. PITSILADIS
*Centre for Exercise Science and Medicine, Institute of Biomedical & Life Sciences, University of Glasgow, Glasgow G12 8QQ, Scotland, U.K.
Correspondence: Dr Y.P. Pitsiladis (e-mail [email protected]).
Search for other works by this author on:
Publisher: Portland Press Ltd
Received:
December 11 2002
Revision Received:
March 19 2003
Accepted:
April 23 2003
Accepted Manuscript online:
April 23 2003
Online ISSN: 1470-8736
Print ISSN: 0143-5221
© 2003 The Biochemical Society
2003
Clin Sci (Lond) (2003) 105 (2): 213–218.
Article history
Received:
December 11 2002
Revision Received:
March 19 2003
Accepted:
April 23 2003
Accepted Manuscript online:
April 23 2003
Citation
Evelina GEORGIADES, Wilhelmina M. H. BEHAN, Liam P. KILDUFF, Marios HADJICHARALAMBOUS, Eileen E. MACKIE, John WILSON, Susan A. WARD, Yannis P. PITSILADIS; Chronic fatigue syndrome: new evidence for a central fatigue disorder. Clin Sci (Lond) 1 August 2003; 105 (2): 213–218. doi: https://doi.org/10.1042/CS20020354
Download citation file:
Sign in
Don't already have an account? Register
Sign in to your personal account
You could not be signed in. Please check your email address / username and password and try again.
Could not validate captcha. Please try again.
Biochemical Society Member Sign in
Sign InSign in via your Institution
Sign in via your InstitutionGet Access To This Article
Open Access for all
We offer compliant routes for all authors from 2025. With library support, there will be no author nor reader charges in 5 journals. Check here |
![]() |