Influence of Diet and Dehydroepiandrosterone on Hypothalamic Monoamine Neurotransmitters in Zucker Rats

Food intake is controlled by hypothalamic neurotransmitters. Exogenous dehydroepiandrosterone (DHEA) decreases Zucker rat caloric intake, alters selection of macronutrients and affects the level of hypothalamic neurotransmitters. The goal of this study was to determine whether the changes induced by the administration of DHEA on hypothalamic neurotransmitters depend on the diet the animals are consuming. Groups of obese, female Zucker rats were fed one of four separate diets: One contained all three macronutrients (fat, carbohydrate and protein). The others consisted of single macronutrients only. Two days later, the animals were treated with 200 mg DHEA/kg body weight (or vehicle only) and then sacrificed the next day. Three hypothalamic regions (the lateral hypothalamic, the ventromedial hypothalamic and paraventricular hypothalamic) were isolated and their content of norepinephrine, epinephrine, dopamine, serotonin and 5-hydroxyindole acetic acid determined. DHEA changed the levels of neurotransmitters compared to untreated controls with the specific changes depending upon the diet the animal had been consuming. In conclusion, DHEA affects both the catecholamine and the serotonin systems, however, diet influences the specific neurochemical changes.