The Effect of 30 Minutes of Passive Stretch of the Rat Soleus Muscle on the Myogenic Differentiation, Myostatin, and Atrogin-1 Gene Expressions

Gomes AR, Soares AG, Peviani S, Nascimento RB, Moriscot AS, Salvini TF. The effect of 30 minutes of passive stretch of the rat soleus muscle on the myogenic differentiation, myostatin, and atrogin-1 gene expressions.ObjectiveTo 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.DesignCase-controlled study.SettingUniversity laboratory.AnimalsFifty 12-week-old male Wistar rats.InterventionsSix 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.Main Outcome MeasuresThe messenger ribonucleic acid (mRNA) levels of myoD, myostatin, and atrogin-1 were assessed by real-time polymerase chain reaction.ResultsTwenty-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.ConclusionsA 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.