Effects of a 60-day confinement on the blood pressure, hormonal responses and body fluids of a mixed crew.
During the EXEMSI experiment, an international crew of 4 subjects (1 woman and 3 men) was confined for 60 days in a normobaric diving chamber (with 1060 mbar atmospheric pressure) to simulate life in a space station and to assess the effects of confinement on psychological and physiological factors. Blood pressure and blood volume regulating hormones (atrial natriuretic peptide, renin, aldosterone) and urine data (24-h urine outputs, ionogram) were measured before (BDC: baseline data collection), during (D: day) and after (R: recovery) confinement. We also measured energy expenditure and total body water, 14 days before, and after 27 days of confinement, by the double-labeled water method. We found a marked increase in 24-h urine output during most of the confinement in the men and the woman. Body weight (-1.8 +/- 0.9 kg) and energy expenditure (-1064 +/- 143 kcal/d, p<0.01) decreased in the 3 men. The total body water (TBW) decreased by 1.5 +/- 1.2 l in the men. Stress was not indicated by plasma and urine catecholamines but plasma growth hormone was elevated on D2 (p<0.01 vs. BDC) in the men. This study shows that confinement conditions can modify body fluid (increases in 24-h urine outputs and TBW changes) and energetic metabolisms.
Maillet
A
A
Laboratoire de Physiologie de l'Environnement (GIP Exercice), Faculte de Medecine Lyon Grange-Blanche, France.
Gunga
H C
HC
Normand
S
S
Allevard
A M
AM
Cottet-Emard
J M
JM
Pachiaudi
C
C
Kirsch
K A
KA
Gharib
C
C
Gauquelin-Koch
G
G
D000222:Adaptation, Physiological; D000328:Adult; D000450:Aldosterone / Q000097:blood; D001273:Atmosphere Exposure Chambers; D009320:Atrial Natriuretic Factor / Q000097:blood; D001794:Blood Pressure / Q000502:physiology*; D001834:Body Water; D001835:Body Weight; D020378:Confined Spaces; D002149:Energy Intake; D004734:Energy Metabolism; D005260:Female; D006728:Hormones / Q000097:blood / Q000378:metabolism*; D006801:Humans; D008297:Male; D009994:Osmolar Concentration; D010953:Plasma Volume; D012083:Renin / Q000097:blood; D012934:Social Isolation; D018561:Space Simulation; D018531:Spacecraft; D016482:Urinalysis; D014882:Water-Electrolyte Balance / Q000502:physiology*; D018474:Weightlessness Simulation
D006728:Hormones; D000450:Aldosterone; D009320:Atrial Natriuretic Factor; D012083:Renin