title: The effect of 30 minutes of passive stretch of the rat soleus muscle on the myogenic differentiation, myostatin, and atrogin-1 gene expressions.
abstract: The effect of 30 minutes of passive stretch of the rat soleus muscle on the myogenic differentiation, myostatin, and atrogin-1 gene expressions.
  
  
  OBJECTIVE
  To evaluate the effect of passive stretch, applied for 30 minutes to the rat soleus muscle, on the myogenic differentiation (myoD), myostatin, and atrogin-1 gene expressions.
  
  
  METHODS
  Case-controlled study.
  
  
  METHODS
  University laboratory.
  
  
  METHODS
  Fifty 12-week-old male Wistar rats.
  
  
  METHODS
  Six groups of animals were given a single stretch bout and were evaluated immediately and 8, 24, 48, 72, and 168 hours later. Another 3 groups were evaluated immediately after 2, 3, and 7 stretches. An intact control group was also analyzed.
  
  
  METHODS
  The messenger ribonucleic acid (mRNA) levels of myoD, myostatin, and atrogin-1 were assessed by real-time polymerase chain reaction.
  
  
  RESULTS
  Twenty-four hours after a single session of stretch only, the myoD mRNA levels had increased compared with the control group, whereas an increase in the atrogin-1 expression was observed after 2, 3, and 7 stretches.
  
  
  CONCLUSIONS
  A single session of passive stretch increased the myoD gene expression, a factor related to muscle growth. Interestingly, daily stretches increased the atrogin-1 gene expression, a gene primarily associated with muscle atrophy. The results indicated that gene expression was responsive to the number of stretch sessions.
authors.affiliation: Unit of Skeletal Muscle Plasticity, Department of Physical Therapy, Federal University of São Carlos, Brazil.
authors.forename: Anna R
authors.initials: AR
authors.lastname: Gomes
authors.forename: Antonio G
authors.initials: AG
authors.lastname: Soares
authors.forename: Sabrina
authors.initials: S
authors.lastname: Peviani
authors.forename: Rubia B
authors.initials: RB
authors.lastname: Nascimento
authors.forename: Anselmo S
authors.initials: AS
authors.lastname: Moriscot
authors.forename: Tania F
authors.initials: TF
authors.lastname: Salvini
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D015870:Gene Expression; D008297:Male; D009124:Muscle Proteins / Q000096:biosynthesis* / Q000235:genetics; D018482:Muscle, Skeletal / Q000378:metabolism*; D017570:MyoD Protein / Q000096:biosynthesis* / Q000235:genetics; D055435:Myostatin; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D017208:Rats, Wistar; D044843:SKP Cullin F-Box Protein Ligases / Q000096:biosynthesis* / Q000235:genetics; D013314:Stress, Mechanical; D016212:Transforming Growth Factor beta / Q000096:biosynthesis* / Q000235:genetics
chemical_list: C525913:Mstn protein, rat; D009124:Muscle Proteins; D017570:MyoD Protein; D055435:Myostatin; D012333:RNA, Messenger; D016212:Transforming Growth Factor beta; C486692:Fbxo32 protein, rat; D044843:SKP Cullin F-Box Protein Ligases