Positive effects of resistance exercise training on cachexia-associated muscle waste, inflammation and oxidative stress in walker-256 tumor-bearing rats.

Abstract

The main of our study was to investigate the effects of resistance exercise training (RE) on prevention of muscle waste, oxidative stress (OS) and inflammation in Walker-256 tumor-bearing rats. Thirty-seven Wistar rats were divided into 4 groups: control group (C,n=9), tumor-bearing (T,n=10), exercised group (E,n=9) and tumor-bearing exercised (TE,n=10). RE protocol consisted of climbing a ladder apparatus with weights tied to the animal's tail. After 6 weeks of RE training, Walker-256 tumor cells were implanted in the right flank. Animals of E and TE continued the RE training for more 12-days. Results showed muscle wasting T group (P75 3.535μm2), body weight loss (-12.2±7.8g), increased systemic leukocytes (20.8±3.4cummx103) and inflammatory interleukins TNF-α (T:8.1±2pg/ml) as well, MDA (T:151.6±13.8 µmol/g protein), lipid hydroperoxide (T:646.1±29.8µmol/g protein) and GSH/GSSG (T:2.1±0.4). In contrast, RE in TE group was able to mitigate body weight loss (3.2±2.3g) and muscle wasting (P75 5.571μm2) with the attenuation of muscle OS MDA (TE:75.25±9.1µmol/g protein), lipid hydroperoxide (TE:305.7±68.6µmol/g protein), GSH/GSSG (TE:3.8±0.3) and systemic inflammatory markers TNF-α (TE:4.4±1.8pg/ml) and increased ant-inflammatory IL-10 (TE:498.9±205.5pg/ml). In conclusion, implantation of Walker-256 tumor promotes weight loss, muscle atrophy and reduced muscle strength. However, RE maintained muscle strength in TE animals and decreased OS and inflammation.