Efeito do estresse crônico na preferência alimentar e na morfologia do pênis de ratos Wistars adultos

Abstract

Stress activates the hypothalamic-pituitary-adrenal axis, increasing the secretion of cortisol and catecholamines. The elevation of glucocorticoids increases the search for pleasurable activities (intake of sugars, fats and drugs). However, it is not yet known whether the increased demand for comfort foods (rich in sugars and fats) can attenuate the deleterious effects of stress or whether it enhances the harmful effect caused by chronic stress. The objective of the study was to evaluate the effects of chronic stress on food preference and penile morphology in adult Wistar rats. Thirty-two 10-week-old adult Wistar rats were used. Divided into four experimental groups: control with standard diet (C, n=8); standard diet stress (S, n=8); control with standard diet + comfort food (CF, n=8) and stress with standard diet + comfort food (SCF, n=8). The animals in groups S and SCF were subjected to chronic stress by restraint.All rats were euthanized when they reached 18 weeks of age, for collection and evaluation of the penis. Capillary blood glucose, body weight and food intake in grams and Kcal/kg were evaluated. In the penis, the total area of the penis, the total area of the cavernous body with and without the tunica albuginea and the area of the tunica albuginea were analyzed. The densities of smooth muscle, connective tissue and sinusoid space of the corpora cavernosa were evaluated. The Kolmogorov-Smirnov normality test was applied. For parametric data, one-way analysis of variance (ANOVA) was used with the application of the Newman-Keuls post-test. For non- parametric data, the Kruskal-Wallis statistical test and the Dunns post test were used. Mean differences were considered significant when the p value <0.05. There was no statistical difference regarding capillary blood glucose at the end of the experiment. The SCF group showed a reduction in body weight at the end of the experiment when compared with the CF group. As for body mass gain, group S showed a reduction in relation to group C. The animals in the SCF group showed a preference for the comfort food type diet compared to the CF group. In group S there was a reduction in the total area of the penis and in the area of the cavernous body with tunica albuginea in comparison with the CF group. There was an increase in connective tissue in groups S and SCF when compared with group C. There was also an increase in connective tissue in S when compared with group CF. There was a reduction in smooth muscle in group C when compared with groups S and SCF. There was muscle reduction in the CF group compared to the SCF group. There was a reduction in the sinusoid space in group C compared to group S. In the other comparisons, there was no statistical difference. We conclude that the animals have a food preference for the comfort food type diet, however the consumption did not change the biometric parameters. Chronic stress was able to decrease the total area of the penis and modify the tissue composition of the corpora cavernosa with replacement of erectile tissue by non-erectile tissue. In morphometric comparisons, comfort food suggests a reduction in the deleterious effects of chronic stress.