title: Effect of head-down tilt bedrest (10 days) on lymphocyte reactivity.
abstract: Immunological responses of six healthy males to 10 days of head-down tilt bedrest (HDT) were assessed. Lymphocyte responsiveness was severely reduced immediately before, during, and immediately after the HDT, even though the lymphocyte numbers did not change. By contrast, delayed-type hypersensitivity was not affected. No dramatic changes were found in WBC counts and lymphocyte subpopulations, with the only exception of natural killer (NK) cells which transiently decreased immediately after HDT. Plasma cortisol levels were elevated above normal immediately before and during the HDT. The data suggest that the mitogenic response of lymphocytes was affected by psychological and fluid shift stress. These results are compared with data obtained during and after spaceflight. We conclude that the stress of HDT induces changes in immunological responsiveness that are strikingly similar to those arising from the stress of spaceflight.
authors.affiliation: Institute of Biotechnology, ETH-Hönggerberg, Switzerland.
authors.forename: F K
authors.initials: FK
authors.lastname: Gmünder
authors.forename: F
authors.initials: F
authors.lastname: Baisch
authors.forename: B
authors.initials: B
authors.lastname: Bechler
authors.forename: A
authors.initials: A
authors.lastname: Cogoli
authors.forename: M
authors.initials: M
authors.lastname: Cogoli
authors.forename: P W
authors.initials: PW
authors.lastname: Joller
authors.forename: H
authors.initials: H
authors.lastname: Maass
authors.forename: J
authors.initials: J
authors.lastname: Müller
authors.forename: W H
authors.initials: WH
authors.lastname: Ziegler
mesh_terms: D000328:Adult; D004837:Epinephrine / Q000097:blood; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D006968:Hypersensitivity, Delayed; D007958:Leukocyte Count; D008213:Lymphocyte Activation; D016131:Lymphocyte Subsets; D008297:Male; D009638:Norepinephrine / Q000097:blood; D013026:Space Flight; D013315:Stress, Psychological / Q000276:immunology; D016683:Supine Position; D014882:Water-Electrolyte Balance / Q000276:immunology; D014893:Weightlessness
chemical_list: D006854:Hydrocortisone; D009638:Norepinephrine; D004837:Epinephrine