Effects of Moderate–Intensity Physical Training on Skeletal Muscle Substrate Transporters and Metabolic Parameters of Ovariectomized Rats

Abstract

A deficit of estrogen is associated with energy substrate imbalance, raising the risk of metabolic diseases. Physical training (PT) is a potent metabolic regulator through oxidation and storage of substrates transported by GLUT4 and FAT CD36 in skeletal muscle. However, little is known about the effects of PT on these carriers in an estrogen-deficit scenario. Thus, the aim of this study was to determine the influence of 12 weeks of PT on metabolic variables and GLUT4 and FAT CD36 expression in the skeletal muscle of animals energetically impaired by ovariectomy (OVX). The trained animals swam 30 min/day, 5 days/week, at 80% of the critical load intensity. Spontaneous physical activity was measured biweekly. After training, FAT CD36 and GLUT4 expressions were quantified by immunofluorescence in the soleus, as well as muscular glycogen and triglyceride of the soleus, gluteus maximus and gastrocnemius. OVX significantly reduced FAT CD36, GLUT4 and spontaneous physical activity (p < 0.01), while PT significantly increased FAT CD36, GLUT4 and spontaneous physical activity (p < 0.01). PT increased soleus glycogen, and OVX decreased muscular triglyceride of gluteus maximus. Therefore, OVX can cause energy disarray through reduction in GLUT4 and FAT CD36 and their muscle substrates and PT prevented these metabolic consequences, masking ovarian estrogen’s absence.

Special Issue on Metabolic Adaptations in Cardiac and Skeletal Muscle during Acute and Chronic Exercise

“…While the benefits of exercise in the treatment of chronic disease are established, the molecular and metabolic adaptations are still not well characterized. This Special Issue of Metabolites presents five original research articles from research laboratories in three separate countries, which demonstrate the ability of chronic exercise training to modulate various aspects of metabolism in both humans [ 3 , 4 ] and rodent models [ 5 , 6 , 7 ]. Moreover, these articles evaluate the potential of exercise training to elicit positive metabolic adaptations in several chronic diseases and conditions.…”

“…The hormonal regulation of metabolic processes is critical in the understanding of adaptations to exercise training. Pejon et al investigated the role of exercise training in mitigating the consequences of aberrant metabolism due to estrogen deficiency [ 7 ]. Ovariectomized (OVX) rats completed a swimming training protocol for 30 min/day, five times/week at 80% critical load over a 12-week period.…”