Regulação dos mecanismos da fome e saciedade em ratos consumidores de sacarose

Abstract

Hunger and satiety are physiological feelings which are responsible to maintaining the balance between the energy consumed and spent in out body. Instabilities in these mechanisms are related to the appearance of several diseases such obesity, hypertension, diabetes etc. Sucrose, which is the common table sugar, has a high glycemic index and is frequently consumed by the general population. The excessive consumption of this carbohydrate has been identified as a public health problem. Therefore, the aim of this study was to investigate the basal food intake in rats with chronic ingestion of 20 % sucrose and some of the mechanisms involved in hunger inhibition. Ten Wistar rats were used in the experiments, divided into two groups. The Control group received treatment with food and water, while the Treated group received food and a 20 % solution of sucrose. After two months of treatment, body weight and basal intake of food and solutions (water or 20 % sucrose) were recorded, and hunger inhibition tests were performed by using two protocols: 1) angiotensin II (ANG II) or saline injections into the lateral ventricle (LV) of the rats; 2) glucostatic test with water or 20 % sucrose 30 minutes before food intake records. The results obtained from the basal intake records showed that the animals of the Treated group ingested, on average, less food (9.25 g) when compared to Control group animals (22.6 g). There was no statistically significant difference between the weight gain of the two groups. However, Treated animals presented an accumulation of epididymal tissue (8.2 g) when compared to Control group animals (2.8 g). Regarding the solution consumption, 20 % sucrose intake values from the Treated group were higher in the second, third and fourth day of register, when compared to the water intake values from the Control group. The results of protocol 1 showed that although the test’s food deprivation has produced hunger in the animals, there was no significant difference in the amount of food ingested by the rats of the different groups during the 2 hours of registration. The results of protocol 2 showed that Control rats that received 20 % sucrose during the test had a higher food intake when compared to Treated animals that received water during the test. Therefore, our study shows that chronic consumption of sucrose 20 % caused a decrease in food intake and an increase in epididymal fat, whereas acute exposure to sucrose 20 % caused a potentiation of hunger after 2 hours of test.