title: Blood volume regulating hormones response during two space related simulation protocols: four-week confinement and head-down bed-rest.
abstract: The volume of regulating hormones (renin, aldosterone, arginine vasopressin and atrial natriuretic factor), electrolytes and creatinine concentrations, and blood pressure were measured in two different four-week experimental protocols: respectively -6 degrees head-down bed-rest (5 subjects) and confinement (6 subjects). We observed a significant increase (P < 0.01 at D2 vs D-5) of systolic blood pressure during confinement and a different level of response for some hormones, especially for arginine vasopressin (300% increase during confinement instead of 50% during bed-rest). The renin-angiotensin-aldosterone system was enhanced during confinement and head-down bed-rest. In both conditions, we obtained a similar pattern of response for blood volume regulating hormones. During confinement, two main factors were inactivity and stress activation of the sympathetic nervous system. In the bed-rest study the response is principally due to the fluid shift and blood volume adaptation but it is not possible to exclude the role of inactivity and stress.
authors.affiliation: Laboratoire de Physiologie de l'Environnement, Faculte de Medicine Lyon Grange-Blanche, France.
authors.forename: A
authors.initials: A
authors.lastname: Maillet
authors.forename: G
authors.initials: G
authors.lastname: Gauquelin
authors.forename: H C
authors.initials: HC
authors.lastname: Gunga
authors.forename: J O
authors.initials: JO
authors.lastname: Fortrat
authors.forename: K
authors.initials: K
authors.lastname: Kirsch
authors.forename: A
authors.initials: A
authors.lastname: Guell
authors.lastname: Bizollon ChA
authors.forename: C
authors.initials: C
authors.lastname: Gharib
mesh_terms: D000328:Adult; D000337:Aerospace Medicine; D000450:Aldosterone / Q000097:blood / Q000378:metabolism*; D001127:Arginine Vasopressin / Q000097:blood / Q000378:metabolism*; D009320:Atrial Natriuretic Factor / Q000097:blood / Q000378:metabolism*; D001510:Bed Rest; D001794:Blood Pressure / Q000502:physiology; D001810:Blood Volume / Q000502:physiology*; D003404:Creatinine / Q000097:blood / Q000378:metabolism; D004780:Environment, Controlled; D018475:Head-Down Tilt; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D011188:Potassium / Q000097:blood / Q000378:metabolism / Q000652:urine; D012083:Renin / Q000097:blood / Q000378:metabolism*; D012146:Rest / Q000502:physiology; D012964:Sodium / Q000097:blood / Q000378:metabolism / Q000652:urine; D018561:Space Simulation; D013315:Stress, Psychological / Q000378:metabolism / Q000503:physiopathology; D018474:Weightlessness Simulation
chemical_list: D001127:Arginine Vasopressin; D000450:Aldosterone; D009320:Atrial Natriuretic Factor; D012964:Sodium; D003404:Creatinine; D012083:Renin; D011188:Potassium