Can daily centrifugation prevent the haematocrit increase elicited by 6-degree, head-down tilt?
A measure to counteract the effects of low or zero gravity is required for long-term space flight, such as the manned Mars mission scheduled by the National Aeronautics and Space administration (NASA) for 2014. We conducted a series of centrifugation experiments with humans, using a short-arm centrifuge (radius 1.8 m, made by First Medical Co., Tokyo, Japan). We employed 6-degree, head-down tilt (HDT) for 4 days to simulate space flight. Ten healthy male volunteers underwent 4-day HDT and a 2-G daily centrifuge load for 60 min in the +Gz direction and measurements, such as haematocrit, 24-h urine volume, body weight and electrocardiogram (ECG) were made. There was no significant increase in the haematocrit during the HDT period, although our previous studies had shown a significant increase during HDT. A 60-min daily load of +2 Gz appears to be effective in reversing the haematocrit increase due to 4-day HDT.
Yajima
K
K
Dept. of Space Medicine, Nihon University Post-graduate School of Medicine, Tokyo, Japan. Yajima@med.nihon-u.ac.jp
Iwasaki
K
K
Sasaki
T
T
Miyamoto
A
A
Hirayanagi
K
K
D000328:Adult; D001510:Bed Rest / Q000009:adverse effects; D001835:Body Weight / Q000502:physiology; D002320:Cardiovascular Physiological Phenomena; D002498:Centrifugation; D004562:Electrocardiography; D018475:Head-Down Tilt / Q000009:adverse effects* / Q000502:physiology*; D006400:Hematocrit; D006801:Humans; D008297:Male; D014556:Urine; D018474:Weightlessness Simulation / Q000009:adverse effects