Fructose‐rich Diet From Weaning To Adulthood: Effects On Sympathetic Activity In Rats

Administration of a diet rich in fructose initiates a series of metabolic events resulting in hypertriglyceridemia, hypertension and glucose intolerance. The purpose of this study was to evaluate the cardiovascular and autonomic modulation induced by fructose intake during 8 weeks. Weaned (21 days old) male Wistar rats (50–60g) were divided in 2 groups and they were followed for 8 weeks: Control (CG) and Fructose (FG, 10% in drinking water). Arterial pressure (AP) and heart rate (HR) were directly recorded using a data acquisition system (Windaq, 2 KHz) in conscious and awake rats. Cardiac autonomic modulation was evaluated using spectral analysis of HR variability and after pharmacological blockade (Atenolol, 8mg/Kg and Atropine, 4mg/Kg). FG showed an increase of mean AP (120±3.1 mmHg) when compared to CG (98±1.6 mmHg). No changes in heart rate were observed, although autonomic balance increased in FG (0.12±0.02) compared to CG (0.04±0.01). Sympathetic tonus was increased in FG (86±7.2 bpm) when compared with CG (49±3.6 bpm) with no differences in vagal tonus. However, intrinsic HR was significantly lower in FG (375±7.2 bpm) when compared with CG (405±8.2 bpm). In conclusion, these data suggest that metabolic changes induced by frutose‐rich diet during life spam in rats are accompanied by hypertension associated with sympathetic overactivity. Supported by: FAPESP(2009/52556‐7) and PIBIC/Mackpesquisa