Effect of exercise and vitamin D on insulin like growth factor-1 level and skeletal muscle autophagy in diabetic rats

Document Type : Original Article

Authors

1 physiology department, faculty of medicine, Mansoura University, Mansoura, Egypt

2 department of physiology, faculty of medicine, mansoura university

3 Department of Medical Physiology,Faculty of Medicine,Mansoura University, Mansoura, Egypt.

4 Physiology department, faculty of medicine, Mansoura University, Mansoura, Egypt

5 veterinarian at medical experimental research center, Mansoura University, Mansoura, Egypt

6 department of physiology, faculty of medicine , mansoura university

Abstract

Background: diabetic myopathy is one of chronic complications of diabetes mellitus, which is evidenced by muscle weakness and atrophy. In our research we aimed to evaluate the protective role of exercise and vitamin D on diabetic induced changes in the skeletal muscles. Methods: Fourty male Sprague Dawely rats were divided into control, diabetic, exercised diabetic, vitamin D treated diabetic and combined exercise and vitamin D diabetic rats. Fasting blood glucose, fasting insulin, HOMA-IR, serum IGF-1 level as well as the contractile properties of soleus and tibialis anterior muscles were measured. Also western blot analysis for measuring (LC3) and histopathological examination of both muscles were done. Results: in diabetic rats, fasting blood glucose, fasting insulin, HOMA-IR and LC3 (microtubule associated protein-1 light chain-3) expression in muscles were increased whereas serum IGF-1 level was decreased and the contractile properties of skeletal muscles were deteriorated. Vitamin D treatment decreased fasting blood glucose, fasting insulin, HOMA-IR and expression of LC3 but it increased serum IGF-1 with improvement in the skeletal muscles contractility. Also exercised diabetic rats revealed improvement in all biochemical parameters, autophagy marker expression with further improvement in the skeletal muscles contractility. Combining exercise and vitamin D treatment showed a more improvement in all studied parameters and the histopathological examination confirmed our results. Conclusion: regular exercise and vitamin D protect the muscles from diabetic induced lesions by improving glycemic state, serum level of IGF-1and suppressing autophagy which finally reflected on the contractile parameters of the muscles.

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