NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Resting Energy Expenditure of Rats Acclimated to Hyper-GravityTo determine the influence of body mass and age on resting energy expenditure (EE) following acclimation to hyper-gravity, oxygen consumption (VO2) and carbon dioxide production (VCO2) were measured to calculate resting energy expenditure (EE), in male rats, ages 40 to 400 days, acclimated to 1.23 or 4.1 G for a minimum of two weeks. Animals were maintained on a centrifuge to produce the hyper-gravity environment. Measurements were made over three hours in hyper-gravity during the period when the lights were on, the inactive period of rats. In rats matched for body mass (approximately 400 g) hyper-gravity increased VO2 by 18% and VCO2 by 27% compared to controls, resulting in an increase in RER, 0.80 to 0.87. There were increases in resting EE with an increase in gravity. This increase was greater when the mass of the rat was larger. Rating EE for 400g animals were increased from 47 +/- 1 kcal/kg/day at 1 G, to 57 +/- 1.5 and 5.8 +/- 2.2 kcal/kg/day at 2,3 and 4.1 G, respectively. There was no difference between the two hyper-gravity environments. When differences in age of the animals were accounted for, the increase in resting EE adjusted for body mass was increased by over 36% in older animals due to exposure to hyper-gravity. Acclimation to hyper-gravity increases the resting EE of rats, dependent upon body mass and age, and appears to alter substrate metabolism. Increasing the level of hyper-gravity, from 2.3 to 4.1 G, produced no further changes raising questions as to a dose effect of gravity level on resting metabolism.
Document ID
20000121132
Acquisition Source
Ames Research Center
Document Type
Preprint (Draft being sent to journal)
Authors
Wade, Charles E.
(NASA Ames Research Center Moffett Field, CA United States)
Moran, Megan M.
(Lockheed Martin Engineering and Science Services Moffett Field, CA United States)
Oyama, Jiro
(NASA Ames Research Center Moffett Field, CA United States)
Schwenke, David
(NASA Ames Research Center Moffett Field, CA United States)
Dalton, Bonnie P.
Date Acquired
August 19, 2013
Publication Date
January 1, 2000
Subject Category
Life Sciences (General)
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

Available Downloads

There are no available downloads for this record.
No Preview Available