title: Use of bed rest and head-down tilt to simulate spaceflight-induce immune system changes.
abstract: Bed rest, both with and without head-down tilt, has been extensively used as an earth-bound analog to study physiologic effects mimicking those occurring in weightlessness during spaceflight. We have been able to show in six subjects that 4 weeks of head-down tilt bed rest induces a significant decrease in interleukin-2 secretion by PHA-stimulated T lymphocytes. Another study, lasting 113 days, with two subjects showed a decreased interleukin-2 receptor expression in PHA-stimulated peripheral blood mononuclear cells but a decreased interleukin-2 production in one subject only. Under the same conditions, interleukin-1 production was largely increased in both subjects. Several other immune parameters were also analyzed. Increased interleukin-1 production could contribute to bone mineral loss encountered during bed rest and decreased interleukin-2 secretion could play a role in the appearance of infectious diseases often observed during bed red.
authors: Laboratoire d'Immunologie, Faculté de Médecine et CHU Rangueil, Toulouse, France.
authors: D A
authors: DA
authors: Schmitt
authors: L
authors: L
authors: Schaffar
authors: G R
authors: GR
authors: Taylor
authors: K C
authors: KC
authors: Loftin
authors: V S
authors: VS
authors: Schneider
authors: A
authors: A
authors: Koebel
authors: M
authors: M
authors: Abbal
authors: G
authors: G
authors: Sonnenfeld
authors: D E
authors: DE
authors: Lewis
authors: J R
authors: JR
authors: Reuben
authors: R
authors: R
authors: Ferebee
mesh_terms: D000917:Antibody Formation; D001510:Bed Rest / Q000009:adverse effects*; D018475:Head-Down Tilt / Q000009:adverse effects*; D006801:Humans; D007107:Immune System / Q000502:physiology*; D007136:Immunoglobulins / Q000097:blood; D007376:Interleukin-2 / Q000378:metabolism; D007958:Leukocyte Count; D008213:Lymphocyte Activation; D008297:Male; D012016:Reference Values; D013026:Space Flight; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D007136:Immunoglobulins; D007376:Interleukin-2