Aerobic exercise training induces metabolic benefits in rats with metabolic syndrome independent of dietary changes

Abstract

OBJECTIVES:We evaluated the effects of aerobic exercise training without dietary changes on cardiovascular and metabolic variables and on the expression of glucose transporter Type 4 in rats with metabolic syndrome.METHODS:Twenty male spontaneously hypertensive rats received monosodium glutamate during the neonatal period. The animals were allocated to the following groups: MS (sedentary metabolic syndrome), MS-T (trained on a treadmill for 1 hour/day, 5 days/week for 10 weeks), H (sedentary spontaneously hypertensive rats) and H-T (trained spontaneously hypertensive rats). The Lee index, blood pressure (tail-cuff system), insulin sensitivity (insulin tolerance test) and functional capacity were evaluated before and after 10 weeks of training. Glucose transporter Type 4 expression was analyzed using Western blotting. The data were compared using analysis of variance (ANOVA) (p<0.05).RESULTS:At baseline, the MS rats exhibited lower insulin sensitivity and increased Lee index compared with the H rats. Training decreased the body weight and Lee index of the MS rats (MS-T vs. MS), but not of the H rats (H-T vs. H). There were no differences in food intake between the groups. At the end of the experiments, the systolic blood pressure was lower in the two trained groups than in their sedentary controls. Whole-body insulin sensitivity increased in the trained groups. Glucose transporter Type 4 content increased in the heart, white adipose tissue and gastrocnemius muscle of the trained groups relative to their respective untrained groups.CONCLUSION:In conclusion, the present study shows that an isolated aerobic exercise training intervention is an efficient means of improving several components of metabolic syndrome, that is, training reduces obesity and hypertension and increases insulin sensitivity.

Changes in blood insulin resistance, GLUT4 and AMPK after continuous and interval aerobic training in normal and diabetic rats

“…For example, white fibers are less affected by aerobic activity in terms of GLUT4 and insulin sensitivity. However, the results of present study are consistent with the findings of Durant (2002) increase of GLUT4 transportation to cell membrane (Paula et al, 2002), Caponi et al (2013) increase of GLUT4 (Caponi et al, 2013), Park et al, (2011) increase of GLUT4 (Park et al, 2011), Zarekar et al (2014) increase of GLUT4 and insulin sensitivity (Zarekar et al, 2014), andCatherine et al, (2013) increase of GLUT4 and improved insulin sensitivity (Katharine et al, 2013). The GLUT4 protein is a major mediator for glucose uptake from blood circulation which is expressed in skeletal muscle and adipose tissue (Huang and Czech, 2007).…”

Swimming training induces liver adaptations to oxidative stress and insulin sensitivity in rats submitted to high-fat diet

“…Several studies [31,32] showed that low-to-moderate PT intensity is effective in inducing benefits by preventing the establishment of MS. In these studies [31,32] PT began with the start of the diet for development of MS. Few studies [1,18] have evaluated PT as a treatment of already established MS. These studies show that PT induces a reduction in systolic blood pressure, together with increased sensitivity to insulin and in the gene expression of GLUT4 in white adipose tissue and gastrocnemius muscle [1], and reduces retroperitoneal and epididymal fat [18,33].…”

“…In these studies [31,32] PT began with the start of the diet for development of MS. Few studies [1,18] have evaluated PT as a treatment of already established MS. These studies show that PT induces a reduction in systolic blood pressure, together with increased sensitivity to insulin and in the gene expression of GLUT4 in white adipose tissue and gastrocnemius muscle [1], and reduces retroperitoneal and epididymal fat [18,33]. In our present study, PT should be considered a treatment because it started in the last 6 weeks of the diets, and therefore with an already established MS disorder, as shown through the increased MAP, HR and body mass of the rats.…”

“…It is generally agreed that an individual's genetic background and lifestyle factors contribute to the pathogenesis of metabolic disorders such as obesity, hyperglycemia, hyperlipidemia and hypertension, or the joint occurrence of these disorders, characterized as metabolic syndrome (MS) [1,2]. Both poor nutrition and physical inactivity are major factors in determining the manifestation of MS, but the exact causes remain unclear.…”

“…Studies on the effect of PT as a treatment and not as prevention of metabolic diseases are few [1,18], and are increasingly important because sedentary individuals have lower adherence to regular practice of PT [19] and therefore have a greater chance of developing obesity and other risk factors for MS. Accordingly, our aim in the present study was to determine the benefit of low-to-moderate-intensity PT, during 6 weeks after MS was established; and the association of these PT levels with cardiovascular parameters, oxidative stress and insulin signaling in the liver.…”