Aerobic exercise training improves Ca2+ handling and redox status of skeletal muscle in mice

Autor(es)

Ferreira, Julio C. B. ; Bacurau, Aline V. ; Bueno Junior, Carlos R. ; Cunha, Telma C. ; Tanaka, Leonardo Y. ; Jardim, Maira A. ; Ramires, Paulo R. ; Brum, Patricia C. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Escola Educ Fis & Esporte, Dept Biodinam Movimento Corpo Humano, BR-05508900 Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Experimental Biology and Medicine; v. 235, n. 4, p. 497-505, APR 2010.
• Citações Web of Science: 37

Resumo

Exercise training is known to promote relevant changes in the properties of skeletal muscle contractility toward powerful fibers. However, there are few studies showing the effect of a well-established exercise training protocol on Ca(2+) handling and redox status in skeletal muscles with different fiber-type compositions. We have previously standardized a valid and reliable protocol to improve endurance exercise capacity in mice based on maximal lactate steady-state workload (MLSSw). The aim of this study was to investigate the effect of exercise training, performed at MLSSw, on the skeletal muscle Ca(2+) handling-related protein levels and cellular redox status in soleus and plantaris. Male C57BL/6J mice performed treadmill training at MLSSw over a period of eight weeks. Muscle fiber-typing was determined by myosin ATPase histochemistry, citrate synthase activity by spectrophotometric assay, Ca(2+) handling-related protein levels by Western blot and reduced to oxidized glutathione ratio (GSH:GSSG) by high-performance liquid chromatography. Trained mice displayed higher running performance and citrate synthase activity compared with untrained mice. Improved running performance in trained mice was paralleled by fast-to-slow fiber-type shift and increased capillary density in both plantaris and soleus. Exercise training increased dihydropyridine receptor (DHPR) alpha 2 subunit, ryanodine receptor and Na(+)/Ca(2+) exchanger levels in plantaris and soleus. Moreover, exercise training elevated DHPR beta 1 subunit and sarcoplasmic reticulum Ca(2+)-ATPase (SERCA) 1 levels in plantaris and SERCA2 levels in soleus of trained mice. Skeletal muscle GSH content and GSH:GSSG ratio was increased in plantaris and soleus of trained mice. Taken together, our findings indicate that MLSSw exercise-induced better running performance is, in part, due to increased levels of proteins involved in skeletal muscle Ca(2+) handling, whereas this response is partially dependent on specificity of skeletal muscle fiber-type composition. Finally, we demonstrated an augmented cellular redox status and GSH antioxidant capacity in trained mice. (AU)

• Processo FAPESP: 06/61523-7 - Aspectos celulares e moleculares da plasticidade muscular
• Beneficiário: Anselmo Sigari Moriscot
• Linha de fomento: Auxílio à Pesquisa - Temático
• Processo FAPESP: 09/03143-1 - Controle de qualidade de proteína na insuficiência cardíaca: papel das diferentes isoformas de proteína quinase C
• Beneficiário: Julio Cesar Batista Ferreira
• Linha de fomento: Bolsas no Brasil - Pós-Doutorado