Efeitos do consumo de dieta hipercalórica no comportamento de consumo de etanol em camundongos fêmeas

Abstract

Given the increase in alcohol consumption among women, the goal of the present study is to validate an animal model of high consumption and alcohol preference in female mice, stimulated by ingesting a hypercaloric diet. To this end, 36 C57BL/6 female mice were subjected to a diet rich in fat and sugar and to the free-choice paradigm of water and 10% ethanol. The model was divided into two stages. In the first stage, 12 animals received the American Institute of Nutrition 93-Growth (AIN93G) diet and 24 animals received a high sugar and butter (HSB) diet for eight weeks. Next, in the second stage, the animals were subdivided equally into the following groups: [1] AIN93G+H2O; [2] AIN93G+EtOH; [3] HSB+H2O; [4] HSB+EtOH; [5] Switch+H2O; [6] Switch+EtOH. The three (+H2O) groups had free access to water, while the three (+EtOH) groups had a free choice between water and a 10% ethanol solution. In the Switch groups, the HSB diet was substituted with the AIN93G diet at the start of the second stage. Stage 2 was conducted for four weeks; then, the animals underwent behavioral tests and, finally, were euthanized. We carried out histological analyses of the liver and the adipose tissue, metabolic analyses of the blood serum using biochemical tests, behavioral analyses using the Marble Burying and light/dark box tests, and an assessment of the transcriptional regulation by RT-qPCR of the Drd1, Drd2, Gabba1 and Gabba2 genes in the prefrontal cortex. The data obtained were compared with those previously obtained for male mice, which are available in the literature, and the statistical analysis was carried out using the Prism 9.3.0. package. In the results with the females, we observed that consumption of the HSB diet increased body weight and adiposity index, postprandial glucose and total cholesterol, while also being responsible for a higher degree of hepatic steatosis in the animals. In the Switch groups, in which this diet was changed to the AIN93G diet, we observed an increase in ethanol consumption, as well as a preference for it. Additionally, the interaction between diet and alcohol consumption modified the behavior of the animals. The animals from the HSB+EtOH and Switch+EtOH groups presented an anxiolytic effect of the alcohol the more time they spent exploring areas exposed to light. Moreover, the Switch+EtOH group also explored a greater area more quickly. We observed a hyper-regulation of the Drd1 gene in the HSB+EtOH group in relation to the HSB+H2O group. In the comparison with the males, we observed that consumption of the HSB diet increased weight, adiposity index, postprandial glucose, total cholesterol and triglycerides more in males than in females. The behavior of increased ingestion and preference for ethanol did not present differences between the sexes in the Switch+EtOH groups, but the males showed greater compulsivity. The interaction between diet and ethanol caused more areas of inflammation in the liver of the females. We observed upregulation in the Drd1 gene in the Switch+H2O and Switch+EtOH groups in the males, in comparison with the females. These results indicate the presence of gender differences in the metabolism, in the behavior of compulsivity and in the transcriptional regulation of the dopamine receptors in the pre-frontal cortex. Thus, we can conclude that we obtained a model of high consumption and preference for ethanol in females. Furthermore, our findings indicate that the differences observed between genders may be related to differential estrogen regulation.