Psychological stress during exercise: immunoendocrine and oxidative responses.
The purpose of this study was to examine the changes in catecholamines (epinephrine [EPI] and norepinephrine [NE]), interleukin-2 (IL-2) and a biomarker of oxidative stress (8-isoprostane) in healthy individuals who were exposed to a dual challenge (physical and psychological stress). Furthermore, this study also examined the possible relationships between catecholamines (NE and EPI) and 8-isoprostane and between IL-2 and 8-isoprostane following a combined physical and psychological challenge. Seven healthy male subjects completed two experimental conditions. The exercise-alone condition (EAC) consisted of cycling at 60% VO(2max) for 37 min, while the dual-stress condition (DSC) included 20 min of a mental challenge while cycling. DSC showed greater EPI and 8-isoprostane levels (significant condition by time interaction). NE and IL-2 revealed significant change across time in both conditions. In addition, following dual stress, EPI area-under-the-curve (AUC) demonstrated a positive correlation with NE AUC and IL-2 AUC. NE AUC was positively correlated with IL-2 AUC and peak 8-isoprostane, and peak IL-2 was positively correlated with peak 8-isoprostane in response to a dual stress. The potential explanation for elevated oxidative stress during dual stress may be through the effects of the release of catecholamines and IL-2. These findings may further provide the potential explanation that dual stress alters physiological homeostasis in many occupations including firefighting, military operations and law enforcement. A greater understanding of these responses to stress can assist in finding strategies (e.g. exercise training) to overcome the inherent psychobiological challenges associated with physically and mentally demanding professions.
Florida Atlantic University, Boca Raton, FL, USA. chuang5@fau.edu
Chun-Jung
CJ
Huang
Heather E
HE
Webb
Ronald K
RK
Evans
Kelly A
KA
McCleod
Supatchara E
SE
Tangsilsat
Gary H
GH
Kamimori
Edmund O
EO
Acevedo
D000328:Adult; D002395:Catecholamines / Q000097:blood*; D015237:Dinoprost / Q000031:analogs & derivatives / Q000097:blood; D015444:Exercise / Q000502:physiology / Q000523:psychology*; D006706:Homeostasis; D006801:Humans; D007376:Interleukin-2 / Q000097:blood*; D008297:Male; D018384:Oxidative Stress; D013312:Stress, Physiological / Q000276:immunology / Q000502:physiology; D013315:Stress, Psychological / Q000276:immunology / Q000378:metabolism / Q000503:physiopathology*
D002395:Catecholamines; D007376:Interleukin-2; C075750:8-epi-prostaglandin F2alpha; D015237:Dinoprost