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Experiment K-7-35: Circadian Rhythms and Temperature Regulation During SpaceflightEnergy expenditure can be regarded as the sum of two components; the basal metabolic rate and the energy costs of activity. Weight loss is usually associated with an energy deficit. A negative energy balance exists when energy intake is less that energy utilization. The deficit is made up by tissue catabolism (principally fat, but also some protein). By analyzing food and water intake, urine and fecal output, and changes in body weight, the Skylab investigators reached the unexpected conclusion that energy expenditure during spaceflight was about 5% greater than at 1 G (Leonard, 1983; Rambaut et al., 1977). Possible explanations for the human metabolic responses are an increased workload during spaceflight (Leonard, 1983), or as Rambaut and co-workers (1977) suggested, a progressive decrease in metabolic efficiency. It is likely to be very difficult to distinguish between these two possibilities in man because the activity component may be different during spaceflight than it is the ground. The problem is to measure energy expenditure with efficient precision during spaceflight in a non-invasive manner which will not interfere with other investigations or take an time. The doubly labeled water (DLW) method meets these criteria. The DLW method is the only method available for continuously measuring energy expenditure during spaceflight given the severely restricted conditions in the spaceflight environment. Therefore, this study focuses on the development and use of this procedure on nonhuman primates during spaceflight. Energy expenditure and total body water was determined in two Rhesus monkeys by the doubly labeled water (2H2'80) method. Three determinations were made. Monkey B (#2483) was studied twice, during the flight of COSMOS 2044 and during a follow-up ground control study a month later. A second monkey was studied on the ground only (Monkey D, #782).
Document ID
19960029012
Acquisition Source
Ames Research Center
Document Type
Other
Authors
Fuller, C. A.
(California Univ. Davis, CA United States)
Dotsenko, M. A.
(Institute of Biomedical Problems Moscow, USSR)
Korolkov, V. I.
(Institute of Biomedical Problems Moscow, USSR)
Griffin, D. W.
(California Univ. Davis, CA United States)
Stein, T. P.
(Medicine and Dentistry Univ. of New Jersey Camden, NJ United States)
Date Acquired
August 17, 2013
Publication Date
September 1, 1994
Publication Information
Publication: US Experiments Flown on the Soviet Biosatellite Cosmos 2044
Subject Category
Life Sciences (General)
Accession Number
96N29607
Funding Number(s)
CONTRACT_GRANT: NAG2-587
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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