161 ACUTE EFFECT OF HIGH-FAT DIET ON AUTONOMIC AND METABOLIC FUNCTIONS IN ADULT RATS

Abstract

Objective: The objective of this study was to evaluate the autonomic and metabolic functions in adult rats subjected to a high-fat diet during 21 days Methods: Adult Male Wistar rats (n = 8/group) were divided in Control Group (CG), commercial rat food, and Hyperlipidic Group (HG), addition of 30% unsalted butter in commercial diet, followed by 21 days. Glucose tolerance test were determinate after intravenous glucose load injection (1.5 g/kg, i.p.). Serum insulin was evaluated by radioimmunoassay. Blood Pressure (BP) and Heart Rate (HR) were directly recorded using a data acquisition system (Windaq, 2 KHz) in conscious and awake rats. Cardiac autonomic activity was evaluated using pharmacological blockade (Atenolol, 8 mg/Kg and Atropine, 4 mg/Kg). Results: At the end of the protocol, body weights and food consumption were similar between the groups. The triglycerides levels was increased in HG (79 ± 5 mg/dL) when compared with CG (40 ± 4 mg/dL). The glucose tolerance was higher in HG (226 ± 12 AUC) when compared to CG (169 ± 16 AUC). Insulin was 26% augmented in HG when compared with CG. There were no differences in BP and HR between the groups. Sympathetic tonus was increased in HG (65 ± 9.2 bpm) compared to CG (37 ± 13 bpm) with no differences in vagal tonus. Intrinsic HR was significantly higher in HG (425 ± 4 bpm) when compared with CG (399 ± 7.2 bpm). Conclusions: In conclusion, our data suggest that acute administration of a high-fat diet was able to promote important metabolic alterations that could be associated with cardiovascular autonomic dysfunction.