A influência da exposição e retirada de uma dieta de cafeteira sobre os parâmetros comportamentais, metabólicos e neuroquímicos de ratos Wistar

Abstract

In recent decades, Brazil has been undergoing a process of nutritional transition, characterized by the rapid decline in the prevalence of malnutrition and high increase rates of overweight / obesity. And it is known that unruly eating habits, such as regular consumption of fast food, high intake of foods with high calorie and fat foods with low fiber content and excessive intake of sweetened drinks are risk factors for obesity. Therefore, we use the cafeteria diet, in order to assess the behavioral and neuroendocrine changes of chronic consumption and permanent withdrawal of this palatable diet during the stages of development. The cafeteria diet consisted of palatable food: snack, wafer, biscuit stuffed sausage and condensed milk. The groups that received this diet had free choice for continuous consumption of water and standard chow. Animals fed diets from day 21 of life and the experiment lasted 7 weeks. 36 Wistar rats were divided into 3 groups, control (C), which received standard diet, cafeteria diet (DC) received cafeteria diet of the 21st day of life until the 70th day of life, and withdrawal (R) which received cafeteria diet until the 35th day of life, it is then replaced by standard feed to 70th day of life. As expected, the cafeteria diet consumption at some stage of life, increased body weight of the animals compared to the control. The animals of the DC group showed an indication of anxious behavior, the task of the open field, for had a higher latency to exit the first square and explore the apparatus. Chronic consumption of this diet led to peripheral metabolic changes such as increased blood glucose, increased plasma leptin, as well as increased abdominal fat, inguinal and increased adrenal weight. However when the DC was removed in adolescence these metabolic parameters returned to the same levels of animals fed standard chow only. In the hippocampus, changes were observed as a decrease in the expression of glucocorticoid receptor (GR) protein of the neuronal nitric oxide synthase (nNos) and the tropomyosin receptor kinase B (TrkB) receptor, and balanced cellular oxidative response. However, these findings indicate that the cafeteria diet throughout life induced an anxious behavior which in part can be explained by the neuroendocrine alterations found in the peripheral metabolism as in the hippocampus of these animals. Also, interesting is that abrupt withdrawal during adolescence was able to reverse, at least in part, some of these changes.