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Effect of hindlimb unweighting on tissue blood flow in the ratThis study characterized distribution of blood flow in the rat during hindlimb unweighting (HU), and post-HU standing and exercise. The relationship between reduced hindlimb blood flow and the previously observed elevation in anaerobic metabolism observed with contractile activity in the atrophied soleus muscle was examined (Witzmann et al., 1992). Blood flow was measured during unweighting, normal standing, and running on a treadmill (15 m/min), after 15 days of HU or cage control. For another group blood flow was measured during preexercise treadmill standing and treadmill running. During unweighting, PE standing, and running no difference in soleus blood flow was observed between groups. Muscles composed mainly of fast twitch glycolytic fibers received greater blood flow during chronic unweighting. With exercise blood flow to visceral organs was reduced in control animals, a similar change was not seen in 15 day HU rats. These changes suggest a reduction in the ability of the sympathetic nervous system to distribute cardiac output after chronic HU. A reduction in blood flow to the soleus during exercise was not observed after HU and so does not explain the increased dependence of the atrophied soleus on anerobic energy production during contractile activity.
Document ID
19920062009
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Mcdonald, K. S.
(NASA Ames Research Center Moffett Field, CA, United States)
Delp, M. D.
(NASA Ames Research Center Moffett Field, CA, United States)
Fitts, R. H.
(Marquette University Milwaukee, WI; Georgia, University, Athens, United States)
Date Acquired
August 15, 2013
Publication Date
June 1, 1992
Publication Information
Publication: Journal of Applied Physiology
Volume: 72
Issue: 6 Ju
ISSN: 8750-7587
Subject Category
Life Sciences (General)
Accession Number
92A44633
Funding Number(s)
CONTRACT_GRANT: NAG2-212
Distribution Limits
Public
Copyright
Other

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