Abstract
Given the impact of cachexia on survival and the quality and life of cancer patients, strategies that attenuate the muscle atrophy are necessary. Among the non-pharmacological, highlight the important role of moderate-intensity aerobic training. However, recent evidence suggests that high-intensity aerobic training is more effective than moderate-intensity aerobic training to promote functional adaptations in skeletal muscle and exercise performance in healthy subjects in chronic diseases such as heart failure and metabolic syndrome. Unfortunately, the effect of high-intensity aerobic training on skeletal muscle in cancer-cachexia models has not yet been evaluated. Moreover, understanding the molecular mechanisms involved in the possible attenuation of muscle atrophy in cancer-cachexia is of necessary. Thus, in this research project we propose an experimental study to assess and compare the impact of moderate-intensity continuous aerobic training and high-intensity interval training in skeletal muscle of tumor-bearing rats. Forty rats will randomize into four groups, namely: 1) control, 2) with cancer and sedentary, 3) with cancer and submitted to moderate-intensity continuous aerobic training and 4) with cancer and submitted to high-intensity interval aerobic training. After six weeks of training, the groups with cancer will be inoculate with Walker 256 tumor. After 14 days of tumor inoculation, the animals will be beheaded. This study will be evaluated the following parameters: the tumor mass, body weight, food consumption, tolerance to exercise, maximal aerobic power, the skeletal muscles function, and cross-sectional area, the activity of the proteasome at the chymotrypsin site, the gene and protein expression of E3 ligases (i.e. Atrogin-1 and MuRF1), the tissue concentration of pro-and anti-inflammatory (e. g. TNF-±, IL-6, IL-1² and IL10) and ubiquinized protein expression in skeletal muscles Soleus and EDL.
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