Therapeutic ultrasound decreases mechano-growth factor messenger ribonucleic acid expression after muscle contusion injury.
OBJECTIVE
To examine the influence of nonthermal ultrasound on mechano-growth factor (MGF) messenger ribonucleic acid (mRNA) expression after blunt trauma.


METHODS
A 2x4 factorial multivariate analysis of variance design.


METHODS
University research laboratory.


METHODS
Thirty-six 3- to 4-month-old male Wistar rats (mean weight, 280.8+/-21.5g). Thirty-two received a bilateral contusion injury to the gastrocnemius via a drop mass technique. Four were control animals.


METHODS
Ultrasound treatment (frequency, 3MHz; intensity, 0.3W/cm(2); continuous duty cycle) was started 24 hours postinjury and delivered for 5 minutes daily on 4 consecutive days. Treatment was on the left hindlimb and the contralateral right hindlimb was the nonultrasound control.


METHODS
Muscle mass (in grams) and MGF mRNA expression as measured via real-time reverse transcriptase polymerase chain reaction.


RESULTS
Ultrasound had no effect on muscle mass (F(1,28)=2.723, P=.110, 1-beta=.357, eta(2)=.089). Ultrasound treatments decreased MGF mRNA expression in the treated limb compared with the nontreated hindlimb (F(1,28)=6.605, P=.016, 1-beta=.699, eta(2)=.191).


CONCLUSIONS
The nonthermal ultrasound treatments resulted in decreased MGF mRNA expression after blunt trauma to the gastrocnemius muscles.
McBrier
Nicole M
NM
Department of Kinesiology, Pennsylvania State University, University Park, PA 16802, USA. nmm13@psu.edu
Lekan
Jaimy M
JM
Druhan
Lawrence J
LJ
Devor
Steven T
ST
Merrick
Mark A
MA
D000818:Animals; D003288:Contusions / Q000378:metabolism / Q000628:therapy*; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D008297:Male; D018482:Muscle, Skeletal / Q000293:injuries / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D014464:Ultrasonic Therapy
D012333:RNA, Messenger; C519382:mechano-growth factor, rat; D007334:Insulin-Like Growth Factor I