Interleukin-6 and tumor necrosis factor-alpha production after acute psychological stress, exercise, and infused isoproterenol: differential effects and pathways.
OBJECTIVE
The aim of the study was to assess the effects of three different methods of acute activation of the sympathetic nervous system on lipopolysaccharide-induced in vitro production of interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha).


METHODS
Thirty-two healthy volunteers performed speech and exercise tasks and underwent a 30-minute infusion of isoproterenol.


RESULTS
As expected, acute activation of the sympathetic nervous system led to leukocytosis, including increases in lymphocyte, monocyte, and granulocyte populations (p values <.05). Lipopolysaccharide-induced IL-6 production was increased after both the speaking and exercise tasks (p values <.001), whereas TNF-alpha production was elevated only after exercise (p<.05). In contrast, infusion of isoproterenol inhibited TNF-alpha production (p<.001) and caused no change in IL-6 production.


CONCLUSIONS
In response to the challenges, IL-6 and TNF-alpha production showed different profiles. Purely beta-agonist stimulation led to downregulation of TNF-alpha production, providing evidence of the antiinflammatory effect of in vivo beta-receptor activation. The enhanced production of both cytokines after exercise, and of IL-6 after the speech task, can be best explained by a simultaneous upregulation of proinflammatory and inflammation-responding mediators. These effects may have an important role in controlling the immune response to acute psychological and physical stress.
Goebel
M U
MU
Department of Psychiatry, University of California, San Diego, La Jolla, USA. marion.goebel@uni-essen.de
Mills
P J
PJ
Irwin
M R
MR
Ziegler
M G
MG
D000328:Adult; D001143:Arousal / Q000187:drug effects / Q000502:physiology; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D007262:Infusions, Intravenous; D015850:Interleukin-6 / Q000097:blood*; D007545:Isoproterenol / Q000494:pharmacology; D007958:Leukocyte Count; D008297:Male; D008875:Middle Aged; D013315:Stress, Psychological / Q000150:complications* / Q000276:immunology; D013564:Sympathetic Nervous System / Q000187:drug effects / Q000502:physiology; D016176:T-Lymphocyte Subsets / Q000187:drug effects / Q000276:immunology; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*; D015854:Up-Regulation / Q000187:drug effects / Q000502:physiology
D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha; D007545:Isoproterenol