title: Excretion of IL-6 by astronauts during spaceflight.
abstract: Ascent to and living under the microgravity conditions found during spaceflight is an unfamiliar environment for humans. The adaptation to the space environment may be perceived by the body as a stress. On the ground, stress results in increased cytokine activity. The objective of this study was to determine whether spaceflight is associated with increased cytokine activity. The mean daily urinary interleukin-6 (IL-6) excretion rate was measured on 24-h urine pools collected from four payload crew members from 11 days before launch to 7 days after landing for a total of 27 days. In addition, in-flight data were obtained from two orbiter crew members. The experiment was conducted before, during, and after the 1991 9.5-day SLS-1 (Columbia) space shuttle mission. Dietary intake and urine output were monitored continuously for the 27-day period for the four payload crew. Results are as follows: 1) urinary IL-6 excretion and cortisol excretion were increased on the 1st day of spaceflight, suggesting an acute-phase response; 2) elevated levels of IL-6 were not found in the urine on any other days before or during flight; and 3) two of the subjects had markedly increased IL-6 excretion rates after landing.
authors.affiliation: Department of Surgery, School of Osteopathic Medicine, University of Medicine and Dentistry of New Jersey, Stratford 08084.
authors.forename: T P
authors.initials: TP
authors.lastname: Stein
authors.forename: M D
authors.initials: MD
authors.lastname: Schluter
mesh_terms: D004032:Diet; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000652:urine; D015850:Interleukin-6 / Q000652:urine*; D008297:Male; D013026:Space Flight
chemical_list: D015850:Interleukin-6; D006854:Hydrocortisone