1 Universidade Federal de Rio de Janeiro - UFRJ Macaé, Brasil.
Introduction: Increased consumption of fructose is associated with metabolic disorders that can to compromise the central nervous system. The insulin act inhibiting the food intake in the hypothalamus. There are scientific evidences that link the high fructose consumption with damage to systems that regulate energy homeostasis. The aim was evaluated if chronic high fructose intake is able to alter the anorexigenic effect of insulin. Methodology: Wistar rats at 30 days of age were randomized in 2 groups: control (C) and fructose (F). Both groups were treated with free access to commercial chow and water (C) or fructose solution 20%. After 60 days, the rats were submitted to stereotactic surgery to hypothalamic infusion of insulin and to examine its anorexigenic response, as well as the content hypothalamic proteins of its signalling pathway using western blotting: insulin receptor (IR), insulin receptor substrate 1 (IRS-1) and phosphorylated forms of IR protein (p-IR) e Akt (p-Akt). Results: The F group did not respond to insulin infusion reducing food intake as well as showed an increased content of IRS-1 and p-Akt. IR and p-IR protein contents did not demonstrate significant difference among groups. Conclusions: The results confirm the hypothesis that chronic treatment with fructose solution is able to alter the anorexigenic action of insulin in Wistars rats. The increased of hypothalamic proteins of signaling pathway suggest a compensatory adaptation that was not accompanied by IR and p-IR proteins. It is suggested that this mechanism can to be involved in limited activity of the pathway.