Effects of long-term eccentric training on the skeletal muscle of mdx mice: morphological and biochemical analyzes

Abstract

Duchene Muscular Dystrophy (DMD) is a recessive degenerative disease linked to the X chromosome. DMD is caused by the absence of the protein dystrophin, which is essential for muscle integrity. A lack of dystrophin leads to muscle weakness and progressive degeneration, and eventually to death due to respiratory failure. Serum dosages of the enzyme creatine kinase (CK) have shown and confirmed significant lesions in muscle tissue resulting from the disease. Eccentric exercise has been used to revert or minimize the morphological and functional alterations observed in dystrophic muscles. In this project we propose to analyze the effects of long-term eccentric exercise over muscle morphology and creatine kinase enzyme (CK) expression of mdx mice. Methods: Male mice (six weeks old) will be divided into four groups: (I) mdx sedentary; (II) mdx trained 37 days on treadmill running; (III) wild type sedentary; (IV) wild type trained 37 days on treadmill running. After the training sessions, animals will be euthanized and sample of blood will be collected to creatine kinase enzyme (CK) expression. To morphological analysis, fragments of skeletal muscles will be removed and submitted to Hematoxilin-Eosin stain technique. Expected Results: The eccentric exercise will be able to improve the cytoarchiteture of muscle tisse and reduce the expression of CK when compared to the respective controls. (AU)