Efeitos do treinamento físico combinado em ratas ooforectomizadas diabéticas: avaliações morfofuncionais, de estresse oxidativo e inflamação cardíacas

Abstract

The incidence of cardiovascular diseases and diabetes significantly increases in women after menopause. Among the chronic diabetes complications is cardiomyopathy, which greatly increases the risk of cardiovascular mortality. On the other hand, aerobic exercise training (ET) induces attenuation of cardiometabolic disorders that affect menopausal women and/or diabetic. However, studies involving the cardiac effects of aerobic ET in association with resistance ET (combined ET) are scarce and controversial. Thus, the aim of this study was to evaluate the effect of combined ET on parameters of morphometry and cardiac function, oxidative stress and inflammation in diabetic ovariectomized rats. Female Wistar rats (200-220g) were divided into 4 groups (n=8 per group): sedentary euglycemic (ES), diabetic (streptozotocin, 50 mg / kg, iv) sedentary (DS) and diabetic ovariectomized (bilateral removal of ovaries) sedentary (DOS) or submitted to combined ET (DOTC). Combined ET was performed on a treadmill and ladder adapted to rats (8 weeks, 5 d/week, 1 h/day), alternating days. Echocardiographic measurements were performed at the end of 8 weeks of ET protocol, and followed the recommendations of the M Mode Standardization Committee of the American Society of Echocardiography. The cardiac oxidative stress was evaluated by chemiluminescence initiated by t-BOOH (QL), the dosage of protein carbonyls and the redox ratio of glutathione (GSH/GSSG). Inflammation was measured by a TNF-α and IL-10 in cardiac tissue. Body weight was lower and blood glucose levels were higher in the diabetic group compared to the ES. Reduction of left ventricular mass (LVM), of relative wall thickness (RWT), and circumferential shortening velocity (VEC), and increased LV cavity in diastole and isovolumetric relaxation time were observed in sedentary diabetic animals (DS group). The combined ET attenuated these morphometric and functional disorders. The myocardial performance index (MPI) indicated a loss in diabetic and improved by physical training (ES: 0.25 ± 0.07; SD: 0.32 ± 0.05; DOS: 0.39 ± 0.13; DOTC: 0.18 ± 0.11). There was an increase of oxidative stress, both assessed by QL as the carbonyl in DOS group (vs. DS group), which was attenuated by combined ET (DOTC group). There was a reduction of GSH/GSSG in all diabetic groups (DS, DOS and DOTC) in relation to euglycemic group (ES), and increase in this parameter in the trained group (ES: 10.4 ± 1.64; SD: 5.8 ± 1.23; DOS: 5.8 ± 0.67; DOTC: 8.6 ± 0.94). There was no difference in TNF-α between studied groups, but IL-10 was decreased in sedentary diabetic groups (DS and DOS groups) regarding the euglycemic (ES group), which was not observed in the trained group (ES: 2.67 ± 1.05; SD: 1.08 ± 0 28; OF: 0.76 ± 0.37; DOTC: 1.84 ± 0.36 pg /mg protein). In conclusion, the results of this study show that the combined exercise training induced attenuation of cardiac morphometric and functional disorders associated with the reduction of oxidative stress and inflammation in the heart in an experimental model of diabetes and menopause, suggesting a positive impact of this approach in the management of risk factors in this condition.