Resistance Training and Ovariectomy: Antagonic Effects in Mitochondrial Biogenesis Markers in Rat Skeletal Muscle

Abstract

Estrogen reduction is associated with a decline in skeletal muscle mitochondrial biogenesis. Molecular events associated with improvements in markers of mitochondrial biogenesis after resistance training and estradiol replacement are unknown. This study aimed to investigate the effects of ovariectomy, resistance training, and estradiol replacement on markers of mitochondrial biogenesis and protein expression related to oxidative capacity in the rat gastrocnemius pool. Estradiol replacement was performed using Silastic(®) capsules. During the 12-week resistance training, animals climbed a ladder with weights attached to their tails. Gene expression was analysed by RT-PCR, and protein content was determined by western blotting. Ovariectomy decreased the gene expression of the mitochondrial biogenesis markers PGC-1α (~73%), NRF-1 (~44%), and TFAM (~53%) (p<0.05) and decreased the protein expression of phosphorylated AMPK, CREB and AKT, which are related to oxidative capacity. Resistance training increased PGC-1α (~59%) and TFAM (~48%) expression compared to the Ovariectomy-Sedentary group. The combination of resistance training and estradiol replacement was superior to the ovariectomy-sedentary and ovariectomy-resistance training treatments regarding the gastrocnemius muscle. Estrogen deficiency altered the expression of genes and proteins that favour the development of a mitochondrial dysfunction phenotype, which was improved with resistance training and was partially improved by estradiol replacement.

Irisin Signaling Pathway is up Regulated by Resistance Training in Ovariectomized Rats

“…This result corroborates with the findings of Barbosa, Shiguemoto, et al which seems to be the first study to present some changes in mitochondrial function in an experimental model of menopause [37]. Our results strengthen the evidence that reduction of estrogen levels is a problem of female physiology that requires further investigation.…”

“…However, RT yielded significantly higher the expression of PGC1-α as well as UCP1 in Ovx-RT. Our results corroborate with the findings of Barbosa, Shiguemoto, et al that also reported lower PGC1-α in Ovx rats and their study showed that the reduction of PGC1-α expression are accompanied by significant reductions in genes and proteins as TFAM and NRF1, which favor mitochondrial biogenesis and also improve the thermogenic machinery [37,[48][49][50]. These data represent an important contribution to understand the relation of exercise, higher mitochondrial biogenesis and thermogenic process as important strategy to prevent the effects of ovariectomy and development of some obesity-related dis-eases.…”

Aromatase deficiency in hematopoietic cells improves glucose tolerance in male mice through skeletal muscle-specific effects

“…Notably, however, tissue analyses also demonstrated higher ERα mRNA expression in skeletal muscle from WT(ArKO) mice, suggesting the possibility that selective loss of aromatase activity in immune cells yielded a compensatory increase in total estradiol signaling within skeletal muscle. A compensatory increase in estradiol signaling is further supported by the fact that skeletal muscle from WT(ArKO) mice showed enhanced expression of genes that are specifically upregulated by 17β-estradiol, including those involved in mitochondrial biogenesis [30]. Further, systemic administration of 17β-estradiol to orchiectomized mice enhanced skeletal muscle glucose uptake due to upregulation of GLUT4 expression [31], another gene that exhibited increased expression in the WT(ArKO) mice relative to WT(WT) controls.…”

Ação Da Vibração De Corpo Inteiro Na Morfologia Do Músculo Tibial Anterior De Ratas Wistar Ooforectomizadas

“…Assim, classificaram essa alteração como um quadro típico de sarcopenia e perda da força e tônus muscular, resultante do déficit hormonal nos grupos ooforectomizados. Barbosa et al (BARBOSA et al, 2016), ao utilizarem o modelo de ooforectomia e avaliarem o músculo plantar, relataram que esse apresenta quantidades equivalentes de fibras do tipo I e do tipo IIA, sendo chamado de músculo misto. De acordo com os pesquisadores, com apenas 12 dias de privação hormonal houve alterações morfológicas e morfométricas nas fibras musculares.…”