Nocturnal plasma levels of cytokines in healthy men.
Nocturnal cytokine levels were measured serially in 12 healthy male volunteers for 12 h, including 8 h of polygraphically monitored nocturnal sleep. Plasma concentrations of interleukin-1 beta (IL-1 beta), interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha) were determined in 30-min intervals by enzyme-linked immunoadsorbent assays. In some subjects cytokines were not detectable at all. In the remaining volunteers (27% for IL-1 beta, 58% for IL-6 and TNF-alpha, respectively) occasional values near to the detection limits (DL) of the assays could be measured. With respect to IL-1 beta and IL-6, plasma levels above the DL were significantly more frequent during sleep than during the preceding time of wakefulness. No temporal association with NREM or REM episodes could be shown. TNF-alpha values above the DL were randomly distributed across the 12-h period investigated. It is concluded that in a considerable percentage of healthy subjects small amounts of cytokines are released at night. Release of IL-1 beta and IL-6 is temporally associated with sleep, whereas the release of TNF-alpha is not. It remains to be established whether nocturnal cytokine release reflects either an interaction between sleep and host defense mechanisms or a sleep-independent circadian rhythmicity.
Gudewill
S
S
Max Planck Institute of Psychiatry, Department of Psychiatry, München, Federal Republic of Germany.
Pollmächer
T
T
Vedder
H
H
Schreiber
W
W
Fassbender
K
K
Holsboer
F
F
D000328:Adult; D002940:Circadian Rhythm; D016207:Cytokines / Q000097:blood*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007375:Interleukin-1 / Q000097:blood; D015850:Interleukin-6 / Q000097:blood; D008297:Male; D017286:Polysomnography; D012890:Sleep / Q000502:physiology*; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis
D016207:Cytokines; D007375:Interleukin-1; D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha