Electrical stimulation prevents immobilization atrophy in skeletal muscle of rabbits.
OBJECTIVE
To investigate the effect of unilateral cast immobilization with and without surface electrical stimulation (ES) on the tibialis anterior (TA) muscle of rabbits.


METHODS
Prospective randomized trial.


METHODS
University medical school.


METHODS
53 New Zealand White rabbits (aged 54 to 63 days, weight 1.73 to 1.91 kg). METHODS AND INTERVENTION: Random assignment, for a 3-week period, to one of four groups: C group (control group), I group (immobilization group), S group (group of electrical stimulation which was stimulated isometrically at 50 Hz, 30 minutes per day, 5 times a week), and IS group (immobilization group which, like the S-group, received electrical stimulation).


METHODS
Muscle wet wight, muscle fiber cross-sectional area, muscle fiber types, and muscle capillary supply.


RESULTS
Muscle wet weight decreased significantly in the I group by 19% (p < or = .05), with a corresponding significant reduction in the total muscle fiber cross-sectional area of 26% (p < or = .05). No significant changes were observed in muscle wet weight and muscle fiber cross-sectional area in the S and IS groups. Interstitial fibrosis was observed in the I group and occasionally in the IS group. No significant changes in the total number of muscle fiber types I and II were found in all experimental groups. The capillary supply of the S and IS groups did not change significantly. However, capillary-to-fiber ratio was significantly reduced by 20% with a simultaneously nonsignificant increase in capillary density (capillaries/mm2) of 11% (p > .05) in the I group. Furthermore, muscle fiber regeneration was observed predominantly in the I group.


CONCLUSIONS
In this experimental model, ES effectively prevented immobilization-induced muscle atrophy by minimizing reduction of muscle fiber cross-sectional area, interstitial fibrosis, and impaired blood supply.
Qin
L
L
Department of Orthopaedics & Traumatology, Prince of Wales Hospital, Chinese University of Hong Kong, Hong Kong.
Appell
H J
HJ
Chan
K M
KM
Maffulli
N
N
D000818:Animals; D004599:Electric Stimulation Therapy; D005260:Female; D007103:Immobilization; D018485:Muscle Fibers, Skeletal / Q000473:pathology; D018482:Muscle, Skeletal / Q000503:physiopathology; D009133:Muscular Atrophy / Q000473:pathology / Q000503:physiopathology / Q000517:prevention & control*; D009929:Organ Size; D011446:Prospective Studies; D011817:Rabbits; D011897:Random Allocation