Exercise training improves the soleus muscle morphology in experimental diabetic nerve regeneration.

INTRODUCTION In this study we evaluate the effects of exercise training (10 weeks) on soleus muscle morphology in diabetic nerve regeneration after injury by sciatic nerve crush. METHODS Wistar rats were assigned to either a non-diabetic (n = 6), non-diabetic injured (n = 6), diabetic (n = 6), diabetic injured (DC; n = 9), or trained diabetic injured group (TDC; n = 7). Muscle transverse sections were used for morphometric and ultrastructural analyses. RESULTS Higher fiber density and smaller average myofiber area were observed in the DC and TDC (P < 0.05) groups compared with the other groups. This atrophic pattern was partially reversed in TDC. There was misalignment of the sarcomeres and structural alterations in the blood vessels, sarcolemma, nucleus, and mitochondria in the DC animals. The myofibers and blood vessels had a similar normal appearance in the TDC group. In addition, polyribosomes, rough sarcoplasmic reticulum, developed Golgi apparatus, and new myofibrils were observed. CONCLUSIONS Sciatic nerve injury was found to promote soleus muscle atrophy and ultrastructural alterations in experimental diabetic nerve regeneration, which were partially reversed by exercise training.