Avaliação metabólica e dos componentes do Sistema Renina-Angiotensina e Atividade Inflamatória em Camundongos submetidos à Restrição Alimentar

Abstract

The increasing prevalence of obesity worldwide has a great impact on public health as the excessive accumulation of body fat is considered a risk factor for cardiovascular disease, and it is one of the main features of the metabolic syndrome (MS). Experimental studies suggest that renin-angiotensin system (RAS) in adipose tissue is influenced by the obesity degree e food restriction in rodents prevents or delays the occurrence of various chronic diseases. The purpose of this study was to evaluate the metabolic profile, the components of the reninangiotensin system and inflammatory activity in epididymal adipose tissue of mice subjected to food restriction. Male Swiss mice were divided into eight groups and were fed for eight weeks with: G1: Standard Diet (ST) ad libitum; G2: ST-20% food restriction; G3: ST-40% food restriction; G4: ST-60% food restriction; G5: High-Fat Diet (HFD) ad libitum; G6: HFD-20% food restriction; G7: HFD-40% food restriction; G8: HFD-60% food restriction. Food intake, body weight, glycemic parameters, lipid profile and albumin were assessed. The weight of epididymal, retroperitoneal, and mesenteric adipose tissues and the area of adipocytes from epididymal adipose tissue were analyzed. The expression of AGT, ACE, ACE-2, IL-6 e TNF-α epididymal adipose tissue was evaluated by real-time PCR. The main findings showed a reduced body weight, improved glycemic and lipid profile, reduced albumin, decreased weights of the epididymal, mesenteric and retroperitoneal adipose tissues and reduced adipocyte size in epididymal adipose tissue of mice submitted to food restriction under standard or high-fat diet. A diminished expression of IL-6, TNF-α, AGT and ACE was detected in the 20% and 40% treatment groups, and increased expression in the 60% caloric restriction groups. In conclusion, we observed that 20% and 40% caloric restriction improved metabolism, controlling the RAS and cytokine expression in mice, while a severe 60% caloric restriction (malnutrition) produced a new pro-inflammatory profile with increased AGT and ACE expression.