Correlation between cardiovascular autonomic control dysfunction and oxidative stress in an experimental model of hypertensive and menopause submitted to fructose overload

Abstract

The aim of this study was to verify the effects of fructose overload in an experimental model of hypertensive and menopause on cardiovascular autonomic control and cardiac oxidative stress. Female SHR rats were divided into (n=8/group): hypertensive (H), hypertensive ovariectomized (HO) and hypertensive ovariectomized submitted to fructose overload (100g/L in drinking water) (FHO). Arterial pressure (AP) signals were directly recorded. Cardiovascular autonomic modulation was evaluated by spectral analysis. Oxidative stress was evaluated by chemiluminescence (CL), total reactive antioxidant potential (TRAP) and redox balance of glutathione (GSH/GSSG) determinations. AP was higher in FHO group (174±4 vs. H: 146±4 HO: 164±5 mmHg) than others groups. FHO group showed reduced vagal tonus (5±3 vs. H: 23±4; HO: 35±7 bpm) and increased sympathetic tonus (91±18 vs. H: 56±11; HO: 60±3 bpm) when compared to other groups. CL was higher in FHO group than other groups. GSH/GSSG was lower in FOH group (8.94±0.80 umol/g) than HO group (13.0±1.4 umol/g). Negative correlation was obtained between VAR-SAP and TRAP (r: –0.71, p≤0.05) and a positive correlation between RMSSD index and GSH/GSSG (r: 0.68, p≤0.05). In conclusion, fructose overload induced impairment in cardiovascular autonomic control associated with increased oxidative stress in hypertensive rats submitted to ovarian hormones deprivation.