High- versus moderate-intensity aerobic exercise training effects on skeletal muscle of infarcted rats
Autor: | José Bianco Nascimento Moreira, Luiz Roberto Grassmann Bechara, Patricia Chakur Brum, Ulrik Wisløff, Paulo Magno Martins Dourado, Luiz H. M. Bozi, Alex Willian Arantes Monteiro, Paulo R. Jannig |
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Rok vydání: | 2013 |
Předmět: |
Male
Proteasome Endopeptidase Complex medicine.medical_specialty Physiology Myocardial Infarction Citrate (si)-Synthase medicine.disease_cause Oxygen Consumption Atrophy Skeletal pathology Hexokinase Physiology (medical) Internal medicine INSUFICIÊNCIA CARDÍACA medicine Animals Aerobic exercise Rats Wistar Muscle Skeletal Ultrasonography Exercise Tolerance business.industry Myocardium Skeletal muscle medicine.disease Myocardial Contraction Exercise Therapy Rats Intensity (physics) Disease Models Animal Muscular Atrophy medicine.anatomical_structure Heart failure Physical therapy Cardiology medicine.symptom business Oxidation-Reduction Glycogen Oxidative stress Muscle Contraction Muscle contraction |
Zdroj: | Repositório Institucional da USP (Biblioteca Digital da Produção Intelectual) Universidade de São Paulo (USP) instacron:USP |
ISSN: | 1522-1601 8750-7587 |
Popis: | Poor skeletal muscle performance was shown to strongly predict mortality and long-term prognosis in a variety of diseases, including heart failure (HF). Despite the known benefits of aerobic exercise training (AET) in improving the skeletal muscle phenotype in HF, the optimal exercise intensity to elicit maximal outcomes is still under debate. Therefore, the aim of the present study was to compare the effects of high-intensity AET with those of a moderate-intensity protocol on skeletal muscle of infarcted rats. Wistar rats underwent myocardial infarction (MI) or sham surgery. MI groups were submitted either to an untrained (MI-UNT); moderate-intensity (MI-CMT, 60% V̇o2 max); or matched volume, high-intensity AET (MI-HIT, intervals at 85% V̇o2 max) protocol. High-intensity AET (HIT) was superior to moderate-intensity AET (CMT) in improving aerobic capacity, assessed by treadmill running tests. Cardiac contractile function, measured by echocardiography, was equally improved by both AET protocols. CMT and HIT prevented the MI-induced decay of skeletal muscle citrate synthase and hexokinase maximal activities, and increased glycogen content, without significant differences between protocols. Similar improvements in skeletal muscle redox balance and deactivation of the ubiquitin-proteasome system were also observed after CMT and HIT. Such intracellular findings were accompanied by prevented skeletal muscle atrophy in both MI-CMT and MI-HIT groups, whereas no major differences were observed between protocols. Taken together, our data suggest that despite superior effects of HIT in improving functional capacity, skeletal muscle adaptations were remarkably similar among protocols, leading to the conclusion that skeletal myopathy in infarcted rats was equally prevented by either moderate-intensity or high-intensity AET. |
Databáze: | OpenAIRE |
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