Resveratrol and grape juice differentially ameliorate cardiovascular autonomic modulation in L-NAME-treated rats

Abstract

Polyphenols consumption detected in red wine and grape juice may prevent or help in the treatment of hypertension. However, cardiovascular autonomic effects of polyphenols were poorly studied. Therefore, we evaluated the effects of resveratrol and grape juice treatments in hemodynamics, baroreflex sensitivity, heart rate (HR) and blood pressure (BP) variability and cardiac redox parameters. Male Wistar rats were divided in 3 groups (n=7/each) and treated for 30 days: only L-NAME-treated (60 mg/kg/day by oral gavage), L-NAME+resveratrol (L-NAME+R) and L-NAME+grape juice (L-NAME+G). BP signal was directly recorded and pulse interval (PI) and systolic arterial pressure (SAP) variability were analyzed in time and frequency domains. Baroreflex sensitivity (BRS) was determined by the alpha index. Oxidized and reduced glutathione concentrations were determined in cardiac tissue. L-NAME increased BP with no differences among groups (mean BP: L-NAME=124±4, L-NAME+R=126±3 and L-NAME+G=125±4 mmHg). PI and SAP variability expressed by total variance were also similar among groups. However, normalized low frequency (LF) and high frequency (HF) components of PI variability were lower and higher, respectively, in both R and G-treated groups when compared to only L-NAME group. Interestingly, sympathetic modulation to the vessels (LF from SAP variability) and BRS were decreased and increased, respectively, only in L-NAME+R rats. Additionally, GSH/GSSG ratios were higher in L-NAME+R and L-NAME+G than in L-NAME group. Our results indicate that resveratrol and grape juice treatments can modulate autonomic function and promote cardiac redox benefits even when nitric oxide is decreased. Moreover, resveratrol influences not only cardiac but also vascular autonomic modulation.

Keywords: Autonomic modulation; Grape juice; L-NAME; Resveratrol.