Characterization of extracellular redox enzyme concentrations in response to exercise in humans

Research output: Contribution to journalArticlepeer-review


  • G Keane
  • T Cullen
  • L James
  • J Vautrinot
  • M Davies
  • B Hussey
  • D Hunter
  • S Mastana
  • A Holliday
  • S Petersen
  • N Bishop
  • M Lindley
  • S Coles

Colleges, School and Institutes


Redox enzymes modulate intracellular redox balance and are secreted in response to cellular oxidative stress, potentially modulating systemic inflammation. Both aerobic and resistance exercise are known to cause acute systemic oxidative stress and inflammation; however, how redox enzyme concentrations alter in extracellular fluids following bouts of either type of exercise is unknown. Recreationally active men (n = 26, mean ± SD: age 28 ± 8 yr) took part in either: 1) two separate energy-matched cycling bouts: one of moderate intensity (MOD) and a bout of high intensity interval exercise (HIIE) or 2) an eccentric-based resistance exercise protocol (RES). Alterations in plasma (study 1) and serum (study 2) peroxiredoxin (PRDX)-2, PRDX-4, superoxide dismutase-3 (SOD3), thioredoxin (TRX-1), TRX-reductase and interleukin (IL)-6 were assessed before and at various timepoints after exercise. There was a significant increase in SOD3 (+1.5 ng/mL) and PRDX-4 (+5.9 ng/mL) concentration following HIIE only, peaking at 30- and 60-min post-exercise respectively. TRX-R decreased immediately and 60 min following HIIE (-7.3 ng/mL) and MOD (-8.6 ng/mL), respectively. In non-resistance trained men, no significant changes in redox enzyme concentrations were observed up to 48 h following RES, despite significant muscle damage. IL-6 concentration increased in response to all trials, however there was no significant relationship between absolute or exercise-induced changes in redox enzyme concentrations. These results collectively suggest that HIIE, but not MOD or RES increase the extracellular concentration of PRDX-4 and SOD3. Exercise-induced changes in redox enzyme concentrations do not appear to directly relate to systemic changes in IL-6 concentration. NEW & NOTEWORTHY Two studies were conducted to characterize changes in redox enzyme concentrations after single bouts of exercise to investigate the emerging association between extracellular redox enzymes and inflammation. We provide evidence that SOD3 and PRDX-4 concentration increased following high-intensity aerobic but not eccentric-based resistance exercise. Changes were not associated with IL-6. The results provide a platform to investigate the utility of SOD3 and PRDX-4 as biomarkers of oxidative stress following exercise.

Bibliographic note

Funding Information: This research was supported by the University of Worcester and the National Institute for Health Research (NIHR) Leicester Biomedical Research Centre. The views expressed are those of the authors and not necessarily those of the NHS, the NIHR or the Department of Health. Publisher Copyright: Copyright © 2019 the American Physiological Society Copyright: Copyright 2019 Elsevier B.V., All rights reserved.


Original languageEnglish
Pages (from-to)858-866
Number of pages9
JournalJournal of Applied Physiology
Issue number3
Publication statusPublished - 1 Sep 2019


  • Antioxidant, Oxidative stress, Peroxiredoxin, Reactive oxygen species, Redoxkine

ASJC Scopus subject areas