Free mobilization and low- to high-intensity exercise in immobilization-induced muscle atrophy.
J Appl Physiol (1985)
; 84(4): 1418-24, 1998 Apr.
Article
in En
| MEDLINE
| ID: mdl-9516212
ABSTRACT
After 3 wk of immobilization, the effects of free cage activity and low- and high-intensity treadmill running (8 wk) on the morphology and histochemistry of the soleus and gastrocnemius muscles in male Sprague-Dawley rats were investigated. In both muscles, immobilization produced a significant (P < 0.001) increase in the mean percent area of intramuscular connective tissue (soleus 18.9% in immobilized left hindlimb vs. 3.6% in nonimmobilized right hindlimb) and in the relative number of muscle fibers with pathological alterations (soleus 66% in immobilized hindlimb vs. 6% in control), with a simultaneous significant (P < 0.001) decrease in the intramuscular capillary density (soleus mean capillary density in the immobilized hindlimb only 63% of that in the nonimmobilized hindlimb) and muscle fiber size (soleus type I fibers mean fiber size in the immobilized hindlimb only 69% of that in the nonimmobilized hindlimb). Many of these changes could not be corrected by free remobilization, whereas low- and high-intensity treadmill running clearly restored the changes toward control levels, the effect being most complete in the high-intensity running group. Collectively, these findings indicate that immobilization-induced pathological structural and histochemical alterations in rat calf muscles are, to a great extent, reversible phenomena if remobilization is intensified by physical training. In this respect, high-intensity exercise seems more beneficial than low-intensity exercise.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Muscle, Skeletal
/
Physical Exertion
Limits:
Animals
Language:
En
Journal:
J Appl Physiol (1985)
Journal subject:
FISIOLOGIA
Year:
1998
Document type:
Article
Affiliation country: