MyoD and Myogenin mRNA Levels after Single Session of Treadmill Exercise in Rat Skeletal Muscle

[Purpose] We examined mRNA levels of MyoD and myogenin in rat skeletal muscle after a single session of treadmill running. [Subjects] A total of 26 male Sprague-Dawley rats aged 4 weeks were used in this study. [Methods] Rats were run on a 16° decline for 30 min. Treadmill speeds were 0, 16, 20, 24 and 28 m/min. At 72 h post-exercise, soleus (SOL) and extensor digitorum longus (EDL) muscles were extracted. The expression of MyoD and myogenin mRNA were analyzed by reverse transcription polymerase chain reaction (RT-PCR) and quantitative RT-PCR. [Results] MyoD and myogenin mRNA expressions were detected in all groups. Significant differences in myogenin levels were apparent in SOL between 16 m/min and 28 m/min. MyoD levels in SOL at 16, 24, 28 m/min were lower, while myogenin levels at 20, 24 and 28 m/min were higher, when compared with the 0 m/min group, although significant differences were not seen. [Conclusion] These results suggest that a single session of exercise has little effect on proliferation of satellite cells, or myotube production.