Avaliação do uso de treinamento de força e/ou do tratamento com estradiol sobre parâmetros ósseos, metabólicos e a adiposidade de ratas adultas ovariectomizadas

Abstract

The increasing taxes of life expectancy, the negative impact of estrogen deficiency has become more significant to women. Both resistance training and hormone replacement therapy have shown capacity of attenuating several deleterious symptoms of menopause. The present study investigated the effects of resistance training and/or hormone replacement on the parameter of bone structure, metabolism and adiposity of adult female ovariectomized rats. In the first stage (protocol 1) it was established the form of hormone treatment. To achieve that, 32 females Wistar were previously evaluated by vaginal cytology (76 days), ovariectomized after 90 days they were born and divided in four experimental groups (n=8/each): Sham (control), OVX (ovariectomized), BED (ovariectomized, treated with estradiol 0,7μg/100g daily) and BEC (ovariectomized, treated with estradiol (1.5μg/100g cyclic). The treatment had its beginning after 120 days they were born, during 21 days. It was analyzed the corporal composition, fat mass, adipocyte tissue morphology. Daily treatment induced negative effects with the reduction on food intake and the growth of the uterine mass, on the adipose tissues there was a reduction of the area, but with the appearing of great deposits of extracellular matrix. The cyclical treatment led to decreased body mass, fat mass, decreased adipocyte area. Therefore the cyclic treatment was chosen to induce positive changes in the tissues evaluated. In the second stage of the study (protocol 2), 40 female Wistar divided in five experimental groups (n=8/each): Sham (control), OVX (ovariectomized), BE (ovariectomized treated with estradiol benzoate), EX (trained ovariectomized) and BE+EX (trained ovariectomized treated with estradiol benzoate), going through a 6-weeks experiment. The resistance training and/or cyclic replacement provided to the bone structure improvement of the microarchitecture with increasing expression of Erα, growth of the bone dimensions, mineral density of the femur the L4 vertebra. On the adipose tissue it was also observed the reduction of the mass and the adipocyte area; on the content of total body fat and of the trunk, increasing of the expression of PPAR-γ and improvements on the glycemic and hormonal profiles. The content of hepatic glycogen was also benefic for both treatments. Hence, there was progress on the expression of PPAR-γ, on the content of hepatic glycogen, on the fat deposits, on the biochemical profile and on the ERαexpression on the osseous tissue. Based on our studies, we concluded that strength training must be considered a worthy tool against deleterious effects provoked by estrogenic deficiency.