NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Interaction of various mechanical activity models in regulation of myosin heavy chain isoform expressionThe purpose of this study was to determine the effects of a novel combination of mechanical activity paradigms on the isomyosin distribution in rat hindlimb muscles. Thirty female Sprague-Dawley rats were divided into five experimental groups as follows: normal control, functional overload (OV) of the plantaris, OV in conjunction with hindlimb suspension (OV-S), and a combination of OV-S and either static standing weight-bearing activity (OV-SS) or high-incline treadmill exercise (OV-SE). OV of the plantaris resulted in significant hypertrophy and significant fast-to-slow isomyosin shifts. These changes were completely inhibited by the addition of hindlimb suspension (OV-S). Also, neither of the two weight-bearing regimes (OV-SS and OV-SE) was able to attenuate the suspension-induced atrophy. In the vastus intermedius and vastus lateralis, however, OV-SS was able to partially retard the atrophy associated with suspension. In both the plantaris and vastus intermedius, only OV-SS was able to partially reverse the slow-to-fast isomyosin transitions associated with suspension. These results suggest that the type of mechanical activity is important in determining adaptation to altered loading conditions, with OV-SS appearing more effective than OV-SE in reversing the effects of unweighting.
Document ID
19930060187
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Diffee, Gary M.
(NASA Ames Research Center Moffett Field, CA, United States)
Mccue, Samuel
(NASA Ames Research Center Moffett Field, CA, United States)
Larosa, Angela
(NASA Ames Research Center Moffett Field, CA, United States)
Herrick, Robert E.
(NASA Ames Research Center Moffett Field, CA, United States)
Baldwin, Kenneth M.
(California Univ. Irvine, United States)
Date Acquired
August 16, 2013
Publication Date
May 1, 1993
Publication Information
Publication: Journal of Applied Physiology
Volume: 74
Issue: 5
ISSN: 8750-7587
Subject Category
Life Sciences (General)
Accession Number
93A44184
Funding Number(s)
CONTRACT_GRANT: NAG2-555
CONTRACT_GRANT: NIH-AR-30346
Distribution Limits
Public
Copyright
Other

Available Downloads

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