Effects of resistance exercise on trophic and atrophic patways in skeletal muscle of rats with paradoxal sleep deprivation

Abstract

Sleep is an important factor in the process of muscle recovery. Changes caused by sleep deprivation and sleep restriction, cause damage in specific hormonal axes, such as hypothalamic-pituitary-adrenal and hypothalamic-pituitary-gonadal axis. The increase on the secretion of corticosterone and decreases testosterone, growth hormone (GH) and insulin-like growth factor-1 (IGF-1) levels, creates a catabolic environment and promotes the process of muscle atrophy. On the other hand, resistance exercise promotes important physiological adaptations, with emphasis on the metabolic, hormonal and intracellular respond by increasing strength, cross-sectional area and maintenance / synthesis of contractile proteins. The aim of this project is evaluate the effects of resistance exercise in the way trophic and atrophic skeletal muscle of rats subjected to deprivation of paradoxical sleep for 96 hours. Will be used male rats, subjected to a protocol of high intensity resistance training for 8 weeks followed by a protocol of paradoxical sleep deprivation for 96 hours. After the animals are euthanized and gastrocnemius muscle blood will be taken for biochemical, histological and blood. To evaluate the anabolic and catabolic hormonal responses will be measured levels of testosterone, IGF-1 and corticosterone. Histology of the gastrocnemius muscle is made with hematoxylin and eosin (HE) and ATPase histomorphometry to evaluate the different types of muscle fibers. Biochemical analysis will be performed by Western blotting of proteins key pathways of synthesis and protein degradation, and the AKT, mTOR, p70S6K1, FOXO, MuRF1, and myostatin and their active forms.