Efeito do treinamento aeróbio de natação no conteúdo de GLUT4 e FAT CD36 e metabolismo energético de ratas ovariectomizadas

Abstract

The end of ovarian secretion of estrogens is associated with imbalance of energy substrates, raising the risk of metabolic diseases. Physical training (PT) corresponds to non-pharmacological treatment in this context, because it is potent metabolic regulator through oxidation and storage of substrates transported by GLUT4 and FAT CD36. However, few is known about the effects of PT on the content of these carriers on ovariectomy (OVX). Therefore, the objective was to analyze the metabolic repercussion of OVX and PT in the from the GLUT4 and FAT CD36 content, under the hypothesis that The PT prevents the unwanted metabolic effects caused by OVX, by not allowing a drop in the content of these proteins. We evaluated 38 Wistar rats divided into 4 groups: control (CG), ovariectomized (GO), exercised (GE) and ovariectomized/exercised (GOE). At 90 days of age GO and GOE had their ovaries extracted through the bilateral OVX technique. At 102 days of GE and GOE were submitted to critical load test, which consisted of 4 maximum swimming efforts with times between 2 and 10 minutes, to determine the intensity of individual critical load (iCC - % of body mass - % BM). GE and GOE swam with 80% iCC, 30 minutes daily/5 days a week, for 12 weeks, with weekly adjustment according to BM. Spontaneous physical activity (SPA) of all groups was measured every two weeks by gravimetric analysis. After 12 weeks of PT, the animals were euthanized. Blood was collected for glycemic analysis; brown adipose tissue (BAT) for mass recording; skeletal muscle (SM) right soleus was directed to quantify FAT CD36 and GLUT4 by immunofluorescence; SM gluteus maximus (GM) and gastrocnemius rights for muscular triacilglycerol analysis (TG); SM soleus, gastrocnemius and GM left for glycogen measurement. The data were presented in mean±standard deviation, submitted to the ANOVA factorial and post hoc variance analysis test of Newman-Keuls for significance level of 5%. OVX promoted BM reduction (F=216.22; p<0.01), without significant effect caused by the PT (F=0.40; p=0.78). OVX reduced SPA (F=6.67; p<0.05), while PT increased (F=19.75; p<0.01). OVX reduced FAT CD36 (F=56.01; p<0.01) and PT increased (F=43.98; p<0.01). OVX reduced GLUT4 content (F=23.43; p<0.01) and PT increased (F=39.28; p<0.01). OVX reduced the mass of BAT relativized by BM (F=11.51; p<0.01) and PT increased (F=35.63; p<0.01). As for muscle glycogen, OVX did not prove changes in the soleus, GM and gastrocnemius (F=1.31; p=0.26; F=1.67; p=0.20 and F=3.91; p=0.05, respectively), while PT promoted an increase in the soleus (F=5.66; p<0.01), without repercussion on the GM and gastrocnemius (F=3.04; p=0.09; F=3.18; p=0.08). Regarding TG, OVX significantly reduced in GM (F=5.27; p<0.05), but did not promote alteration in gastrocnemius (F=1.68; p=0.20). PT did not change significantly in GM (F=1.71; p=0.20) and gastrocnemius (F=2.88; p=0.10). OVX increased blood glucose (F=9.57; p<0.01) and PT decreased (F=27.66; p<0.01). In general, OVX caused damage in metabolic parameters, while PT promoted improvement in these parameters, presenting similar results and eventually optimized in relation to control.