Efeito do treinamento resistido sobre o coeficiente de controle de fluxo mitocondrial do cortex pré-frontal de ratas ovariectomizadas

Abstract

Introduction: During the aging of a woman, a process called menopause takes place, marked by hormonal changes (fall in estrogen, increase in follicle stimulating and luteinizing hormone). As a result of this phase, there are episodes of changes in brain functions (cognitive deficit, mood change and sleep disorders) that are sensitive to this hormonal variation, mainly related to the drop in estrogen, which in turn directly compromises the activity of an organelle, the mitochondria. It is suggested that resistance training improves mitochondrial functions, bringing non-pharmacological benefits to women who are in this phase. Mitochondrial function can be measured through cellular respiration, but the FCC method can also be used, which calculates the individual functioning of each protein that is coupled to the electron transport chain (ANT-1, ATP synthase and the phosphate exchanger) . Objectives: to evaluate the effects of ovariectomy and Resistance Training (RT) on the efficiency of the flow control coefficient (FCC) and oxygen consumption during coupled breathing of the Prefrontal Cortex of young mature rats, to evaluate the effects of ovariectomy and resistance training on the global and intrinsic functioning of the mitochondrial electron transport chain complexes of prefrontal cortex neurons, the activity of ANT-1, ATP-Synthase and Phosphate Exchanger in an "in vivo" model (biopsy ) of neurons in the prefrontal cortex. Methodology: 40 adult Wistar rats (rattus albinus norvergicus) were divided into 4 experimental subgroups: 1) Intact Sedentary (INT-SED), Intact Resistance Training (INT-TR), Sedentary Ovariectomized (OVX-SED) and Ovariectomized Resistance Training (OVX-TR), for the TR group, the training frequency happened 3 times a week for 12 weeks and the intensity was applied at 65%, 70%, 75%, 80% and 85% of the maximum load carried. Oxygen consumption of permeabilized brain tissue was performed in a high resolution oxygraph with MiR05, 37ºC, in the presence of glutamate (10 mM) and malate (5 mM). ADP (400 μM), oligomycin (1 μg/mL) and FCCP (carbonyl cyanide-4) (trifluoromethoxy) phenylhydrazone 0.2 μM] were added during the experiment. The titrations to establish the Flow Control Coefficient (FCC) were carried out in the ANT, in the Phosphate Exchanger and in the ATP-Synthase. Results: Ovariectomy increased the body mass of the rats, tibia size there was no significant difference, thus showing that all rats had similar growth. Ovariectomy negatively affected the FCC of ANT-1, ATP synthase in the OVX-SED group, and the phosphate carrier. The negative effects of ovariectomy were reversed by RT. Discussion: ovariectomy promoted a decrease in the functioning capacity of the electron transport chain in the prefrontal cortex, evaluated by the FCC dysfunction found in all analysis proteins, ANT-1, ATP-Synthase and Phosphate Exchanger, a fact in A highlight was the use of RT as an important therapeutic tool to reverse the deleterious effects caused by ovariectomy on the FCC of the mitochondrial respiratory chain of trained rats. Conclusion: The deleterious effects of ovariectomy negatively impact the functioning of the mitochondrial respiratory chain in the prefrontal cortex, a fact related to the negative changes in the proteins evaluated in this study by the flow control coefficient. The applied resistance training proved to be effective in preventing the deleterious changes promoted by ovariectomy, since the evaluated proteins maintained their activities at satisfactory levels.