Muscle recovery after immobilisation by external fixation.
We immobilised the right hindlimbs of six-month-old female Wistar rats for four weeks using a biplanar external fixation bridging the knee. The untreated left limbs served as a control group. An additional group of rats was allowed to recover for four weeks after removal of the frame. Immobilisation caused reduction in the wet weights of approximately 50% in the gastrocnemius, quadriceps, soleus and plantaris muscles; this was not restored completely after remobilisation. There was an increase in the activity of acid phosphatase of approximately 85% in the gastrocnemius and quadriceps muscles whereas that of creatine phosphokinase was reduced by about 40%. These values returned to nearly normal after remobilisation. Histological and ultrastructural examination showed a marked myopathy of the gastrocnemius muscle after immobilisation although the morphology was largely restored after remobilisation. We conclude that after four weeks of remobilisation, hind-limb muscles do not return to preimmobilisation weights, although biochemical activities and ultrastructural appearance are largely restored.
Zarzhevsky
N
N
Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology and the Rambam Medical Centre, Haifa.
Coleman
R
R
Volpin
G
G
Fuchs
D
D
Stein
H
H
Reznick
A Z
AZ
D000135:Acid Phosphatase / Q000378:metabolism; D017667:Adipocytes / Q000648:ultrastructure; D000818:Animals; D001835:Body Weight; D002467:Cell Nucleus / Q000648:ultrastructure; D003402:Creatine Kinase / Q000378:metabolism; D016267:External Fixators / Q000009:adverse effects*; D005260:Female; D007103:Immobilization / Q000009:adverse effects*; D015227:Lipid Peroxidation / Q000502:physiology; D018482:Muscle, Skeletal / Q000378:metabolism* / Q000473:pathology*; D009210:Myofibrils / Q000648:ultrastructure; D009929:Organ Size; D011184:Postoperative Period; D051381:Rats; D017208:Rats, Wistar
D003402:Creatine Kinase; D000135:Acid Phosphatase