IMPACTO DO TREINAMENTO FÍSICO SOBRE ALTERAÇÕES NO PERFIL OXIDATIVO E PARÂMETROS MORFOFUNCIONAIS CARDIOVASCULARES EM UM MODELO ANIMAL DE OBESIDADE INDUZIDA POR DIETA HIPERCALÓRICA

Abstract

Introduction: Obesity is characterized as a chronic and complex condition, which contributes to negative impacts on human health. In its genesis, genetic, environmental, metabolic and behavioral factors act that can determine a reduction in quality of life, predisposing to metabolic and cardiovascular changes. Faced with this problem, physical exercise is an important strategy for reducing body adiposity and preventing cardiovascular disorders associated with obesity. Objective: To evaluate the impact of physical exercise on changes in the oxidative profile and cardiovascular morphofunctional parameters in an animal model of obesity induced by a high-calorie diet. Methods: We used 24 male Wistar rats weighing between 150 and 200g, whose study protocol was approved by the Ethics Committee on the Use of Animals (CEUA/IMS-UFBA) under opinion number 053/2017. Initially, the experimental animals were subjected to a normocaloric control diet (DC, n=10) or a hypercaloric diet (DH, n=14) to induce obesity for 8 weeks. After this period, the animals in the control diet group (CD) or the hypercaloric diet group (HD) were subdivided into 2 experimental groups each, which were trained on a motorized treadmill (DCT, n=5; DHT, n=7) or maintained sedentary (DCS, n=5; DHS, n=7) for 12 weeks. At the end of the experiment, the abdominal adipose tissue deposits were dissected, weighed and the ventricle and aorta were removed for histological analysis. Chest blood was collected for biochemical and hormonal analysis. The histological sections were stained with Hematoxylin-Eosin (HE) and Masson's Tricromion (TM) and analyzed by the computerized system (ImageJ). Results: The high-calorie diet resulted in an increase in food and caloric intake, body weight and adiposity and altered glucose tolerance. The training protocol applied reduced body weight, adiposity index and abdominal adipose tissues of animals submitted to the high-calorie diet. No significant changes were observed in fasting blood glucose, insulin, HOMA-IR, HOMA-and Quick. Systolic blood pressure increased in sedentary animals that consumed the high-calorie diet and was reduced by the physical training protocol by approximately 12%. CK/MB levels were reduced in trained animals compared to sedentary animals submitted to a high-calorie diet. Animals submitted to a high-calorie diet had larger areas in the thickness of the aortic tunica intima, consequently, these animals had smaller aortic lumens; while trained animals had smaller thicknesses and larger lumens. The areas of cardiomyocytes and capillarization demonstrated pathological cardiac adaptations in sedentary animals that consumed a high-calorie diet, while in trained animals’ physiological cardiac adaptations were noted with an increase in cardiomyocytes and neocapillarization. Sedentary animals submitted to a high-calorie diet showed larger areas with fibrosis while the training protocol reduced these areas. The training applied in this study increased catalase and GPX values, while lipid peroxidation was reduced in trained animals. Cardiac total nitrite levels were higher in the (DHS) group and in the trained groups regardless of diet. Conclusion: The training protocol determined an improvement in body adiposity, oxidative profile and cardiovascular morphofunctional parameters in the animal model of diet-induced obesity.