BACKGROUND: Skeletal muscle has the ability to adapt to several stimuli, such as contractile activity as well as direct and indirect damage. Aquatic therapy has been used in the rehabilitation of musculoskeletal disorders. In addition, it has demonstrated positive results in the therapeutic process and preventing several diseases.. OBJECTIVE: The aim of the present study was to analyze the effect of swimming on the expression of the myogenic regulatory factors MyoD and myogenin during the skeletal muscle repair process in rats following cryoinjury. METHODS: Forty Wistar rats were randomly divided into four groups: 1) Control; 2) Sham - non-muscle damaged, submitted to procedure for exposure of the tibialis anterior (TA) muscle; 3) Cryoinjured; and 4) Cryoinjured and submitted to swimming. Analyses were carried out at 7, 14 and 21 days. Cryoinjury was performed with two applications of the flat end of a metal rod previously cooled in liquid nitrogen directly to the belly of the TA muscle. The protocol consisted of 90-minute swimming sessions six times a week. At the end of the protocol, the animals were euthanized and the TA muscles were removed. Total RNA was extracted using the TRIzol reagent. Next, cDNA was obtained to perform real-time PCR using specific primers for MyoD and myogenin. RESULTS: The results showed a reduction in the expression of myogenin in the groups cryoinjury with p<0.01and without p <0.01 swimming after 7 days, and in group cryoinjury with swimming (p<0.05) after 14 days respect to the control groups and "sham", respectively. There were no differences between groups cryoinjury with (p> 0.05) and without (p>0.05) swimming. Regarding the expression of MyoD there was no difference between the groups. CONCLUSION: Swimming did not affect the expression of myogenic regulatory factors during the skeletal muscle repair process in rats following cryoinjury.
swimming; repair; skeletal muscle; MyoD
