title: Diurnal and sleep-wake dependent variations of soluble TNF- and IL-2 receptors in healthy volunteers.
abstract: There is very little published information on the diurnal variation of cytokines and their receptors, in healthy individuals during normal sleep-wake patterns or during sustained wakefulness. The aim of the current investigation was to characterize concentrations of soluble tumor necrosis factor receptors (sTNF-Rs) and interleukin-2 receptor (sIL-2R) during normal sleep and wakefulness, as well as during a 24 h vigil. Plasma levels of the sTNF-R p55, sTNF-R p75, and sIL-2R did not differ significantly between nocturnal sleep and nocturnal wakefulness. Rhythmic analysis (2-h intervals) revealed significant diurnal variations for both sTNF-R p55 and sTNF-R p75, but not levels of sIL-2R. Diurnal variations of both sTNF-Rs were characterized by a single cosine curve with an average peak near 06:00 h in the morning. This peak occurred well before that of cortisol, and fluctuated inversely with the diurnal rhythm of temperature. These diurnal variations in sTNF-Rs levels are consistent with the hypothesis that the TNF system plays a role in normal diurnal temperature regulation.
authors.affiliation: Department of Neurology, Beth Israel Deaconess Medical Center and Harvard Medical School, 330 Brookline Avenue, DA 779, Boston, MA 02215, USA.
authors.forename: Monika
authors.initials: M
authors.lastname: Haack
authors.forename: Thomas
authors.initials: T
authors.lastname: Pollmächer
authors.forename: Janet M
authors.initials: JM
authors.lastname: Mullington
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D015703:Antigens, CD / Q000097:blood*; D002940:Circadian Rhythm / Q000276:immunology* / Q000502:physiology; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D008297:Male; D015375:Receptors, Interleukin-2 / Q000097:blood*; D018124:Receptors, Tumor Necrosis Factor / Q000097:blood*; D047888:Receptors, Tumor Necrosis Factor, Type I; D047889:Receptors, Tumor Necrosis Factor, Type II; D012016:Reference Values; D012890:Sleep / Q000502:physiology; D012892:Sleep Deprivation / Q000097:blood*; D014851:Wakefulness / Q000502:physiology
chemical_list: D015703:Antigens, CD; D015375:Receptors, Interleukin-2; D018124:Receptors, Tumor Necrosis Factor; D047888:Receptors, Tumor Necrosis Factor, Type I; D047889:Receptors, Tumor Necrosis Factor, Type II; D006854:Hydrocortisone