Efeito do treinamento resistido na função mitocondrial e na expressão gênica da UCP-3 no músculo de ratas ovariectomizadas

Abstract

Introduction: Menopause is defined as an interruption of menstruation resulting from loss of activity of ovarian follicles. One of the main deleterious effects of this phase is sarcopenia, resulting in loss of strength and muscle mass. In the expectation of better elucidating the aspects related to this period, the models of ovarian removal in rats (OVX) were used to mimic the menopause, being effective in reproducing deleterious effects related to this period. Few studies have investigated the effect on the electron transport chain (ETC) and its relation with the gene expression of UCP-3 in OVX rats, as well as the effects of resistance training (RT) in the scenario. Objective: The present study has as main objective to investigate the effects of OVX and the intervention of the RT in the functioning ETC during the coupled respiration and the decoupled respiration as well as in the gene expression of UCP-3. Materials and Methods: We used 40 rats adults, distributed in 4 experimental groups (ShamSed, ShamRT, OVXSed and OVXRT). Ovariectomy was performed at 13 weeks. The RT realized was the stair climbing model, performed for 22 weeks. The body mass of interest was analyzed after the sacrifice, which happened 48 hours after the last training. The oxygen consumption and the mitochondrial respiratory parameters were realized in tissue biopsy of the Gastrocnemius muscle and Soleus muscle by the technique the High Resolution Respirometry (Oroboros®). The same muscle of opposite leg was frozen at -80 ° C for analysis of the UCP-3 gene expression. Statistical treatment was used test of homogeneous and homogeneity followed normality test in ANOVA and Tukey Post-Hoc test (p <0.05). Results: Ovariectomy increased the gene expression of UCP-3 and RT program was able revert this increase. In addition, no decoupled state (E4, inhibition of ATP-synthase) there was an increase in oxygen consumption in the OXSed group, reversed by TR. The coupled respiration (E3, stimulated by ADP) showed a significant reduction in the respiration velocity of the OVXSed group for both muscles than other 3 groups, and the same action was observed for respiratory control, indicated by the ratio of E3 and E2. Conclusion: We results allow us concluded that an ovariectomy affects a mitochondrial function in the muscle and the gene expression of UCP-3 in rats OVX sedentary and that the RT program is able to prevent these responses.