Effects of resistance training on irisin signaling pathway of ovariectomized rats

• Grant number: 13/06952-3
• Support Opportunities: Scholarships in Brazil - Master
• Effective date (Start): July 01, 2013
• Effective date (End): June 30, 2015
• Field of knowledge: Biological Sciences - Physiology - Physiology of Effort
• Principal Investigator: Sergio Eduardo de Andrade Perez
• Grantee: Natalia Santanielo Silva Magosso
• Host Institution: Centro de Ciências Biológicas e da Saúde (CCBS). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil

Abstract

The increase on women's life spam has brought a growing interest on aging-related issues. Menopause is associated with a larger risk of several impairing metabolic disorders that reduce quality of life. Studies point that women on this condition show a reduction of muscle mass and bone mineral density, higher fat deposition, negative changes in lipid profile, higher levels of inflammatory markers, reduction in oxidative capacity, insulin resistance and cardiovascular diseases. In this sense, it is of notorious importance to study the efficacy of non-pharmacological interventions that reverse this deleterious state, given that hormonal reposition therapy implies in augmented risk of cancer. Thus, physical activity is indicated to attenuate these symptoms, and resistance training must be considered as such. Previous work of our group shows that resistance training positively modulates several tissues and minimizes some of the deleterious effects of the reduction in estrogen levels in humans and animals. Recently, a hormone called irisin was discovered and pointed as an agent of the beneficial effects of exercise. Exercise increases the expression of PGC1± in skeletal muscle, which induces the production of FNDC5, a membrane protein that when cleaved releases irisin to the blood stream. Irisin then promotes an increase in UCP1 in white adipose tissue and induces its browning. The purpose of the study is to investigate the effects of resistance training and hormonal reposition therapy on serum levels of irisin, gene and protein expression of factors of irisin signaling and the browning of white adipose tissue of ovariectomized rats.