Expression of myogenic regulatory factors in rat skeletal muscles after denervation

Aim: The aim of this study was to investigate expression of myogenic regulatory factors MyoD and myogenin during denervation in fast and slow rat skeletal muscles of different rat strains (Wistar and Sprague-Dawely). Material and Methods: Immunohistochemical andWestern blot analyses were performed on tibialis anterior and soleus muscles. Results: Immunohistochemical analysis of tibialis anterior and soleus muscles during denervation demonstrated that both myonuclei and satellite cells were activated.Western blot analysis showed a significant upregulation of MyoD and myogenin proteins in m. tibialis anterior at all time points of denervation, except on 60th day for MyoD. In m. soleus during denervation Western blot analysis showed upregulation of MyoD and myogenin in first 14 days, and there was no expression after that period. Conclusion: Our results indicate that MyoD and myogenin protein expression during denervation is muscle type specific. The role of MyoD and myogenin in adult muscle is potentially also important in orchestrating an adaptive response of existing muscle fibers during denervation