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Rat limb unloading - Soleus histochemistry, ultrastructure, and electromyographyThe effects of hindlimb unloading on rat-soleus histochemisty, ultrastructure, and electromyogram (EMG) activity were investigated. It was found that, after 14 days of tail suspension, the area of type I and type IIa muscle fibers decreased by 63 and 47 percent, respectively, mainly due to the degradation of subsarcolemmal mitochondria and myofibrils. After 10 days, 3 percent of type IIa fibers exhibited segmental necrosis. After four days, video monitoring revealed abnormal plantar flexion of the hindfeet, which shortened the soleus working range. The EMG activity shifted from tonic to phasic, and aggregate activity decreased drastically after only seven days. The results indictate that the pathological changes in the soleus resulted from unloaded contractions, reduced use, compromised blood flow, and shortened working length.
Document ID
19900057219
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Riley, D. A.
(Medical Coll. of Wisconsin Milwaukee, WI, United States)
Slocum, G. R.
(Medical Coll. of Wisconsin Milwaukee, WI, United States)
Bain, J. L. W.
(Medical Coll. of Wisconsin Milwaukee, WI, United States)
Sedlak, F. R.
(Medical Coll. of Wisconsin Milwaukee, WI, United States)
Sowa, T. E.
(Wisconsin Medical College, Milwaukee, United States)
Date Acquired
August 14, 2013
Publication Date
July 1, 1990
Publication Information
Publication: Journal of Applied Physiology
Volume: 69
ISSN: 0161-7567
Subject Category
Life Sciences (General)
Accession Number
90A44274
Funding Number(s)
CONTRACT_GRANT: NAG2-552
CONTRACT_GRANT: NAG2-460
Distribution Limits
Public
Copyright
Other

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