Increased oxidative stress and impaired antioxidant defence are important mechanisms in the pathogenesis of diabetic neuromyopathy. Since diabetes mellitus type 1 decreases muscle regeneration capacity the present study was designed to determine the influence of alpha-lipoic acid (ALA), a potent biological antioxidant, on the process of regeneration of diabetic rat skeletal muscles. The regeneration process was provoked in streptozotocin induced diabetic rats in both slow (m.soleus, SOL) and fast (m.extensor digitorum longus, EDL) skeletal muscles by intramuscular injection of myotoxin bupivacain. At intervals of ten days and four weeks, muscle histochemical and morphometrical analysis (fibre cross areas and fibre type distribution) was performed. Changes induced by diabetes are evident in redistribution of muscle fibers and in significant level of atrophy. After four weeks of diabetes, glycolytic muscle fibers are dominant in both slow and fast muscles. Muscle atrophy is present in all fiber types except in type I of slow skeletal muscle. Our results have shown that treatment with lipoic acid can reduce changes in the morphological properties caused by diabetes mellitus in slow and fast rat skeletal muscles during the process of regeneration. Treatment with lipoic acid during four weeks has shown effects on the redistribution of muscle fibers, and can prevent atrophy in slow and fast diabetic muscle.

Fundamental medical sciences