Exercise elevates plasma levels but not gene expression of IL-1beta, IL-6, and TNF-alpha in blood mononuclear cells.
Physical activity induces a subclinical inflammatory response, mediated in part by leukocytes, and manifested by elevated concentrations of circulating proinflammatory cytokines, including interleukin (IL)-1beta, IL-6, and tumor necrosis factor-alpha (TNF-alpha). However, the source of the cytokines that appear during exercise remains unknown. In this study, we examined exercise-induced changes in plasma cytokine concentrations and their corresponding mRNA expression in peripheral blood mononuclear cells. Ten healthy [peak oxygen uptake = 48.8 +/- 6.5 (SD) ml. kg(-1). min(-1)] but untrained men [age = 25 +/- 5 (SD) yr] undertook 3 h of exercise (cycling and inclined walking) at 60-65% peak oxygen uptake. Circulating leukocyte subset counts were elevated during and 2 h postexercise but returned to normal within 24 h. Plasma concentrations of IL-1beta, IL-6, and TNF-alpha peaked at the end of exercise and remained elevated at 2 h (IL-6) and up to 24 h (IL-1beta and TNF-alpha) postexercise. Cytokine gene expression in circulating mononuclear cells was measured by using the reverse transcriptase-polymerase chain reaction; mRNA accumulation did not change with exercise. In conclusion, mRNA accumulation of IL-1beta, IL-6, and TNF-alpha in circulating mononuclear cells is not affected by 3 h of moderate endurance exercise and does not seem to account for the observed increases in plasma cytokines.
Moldoveanu
A I
AI
Graduate Department of Community Health, Faculty of Medicine, University of Toronto, Toronto M5S 2W6, Ontario, Canada M3M 3B9.
Shephard
R J
RJ
Shek
P N
PN
D000328:Adult; D015444:Exercise / Q000502:physiology; D005786:Gene Expression Regulation / Q000276:immunology*; D006801:Humans; D007375:Interleukin-1 / Q000097:blood* / Q000235:genetics; D015850:Interleukin-6 / Q000097:blood* / Q000235:genetics; D007958:Leukocyte Count; D007963:Leukocytes, Mononuclear / Q000276:immunology*; D008297:Male; D010101:Oxygen Consumption; D005082:Physical Exertion / Q000502:physiology*; D012333:RNA, Messenger / Q000097:blood / Q000235:genetics; D014158:Transcription, Genetic / Q000276:immunology*; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics / Q000378:metabolism*
D007375:Interleukin-1; D015850:Interleukin-6; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha