Nitric oxide bioavailability: effect of (?)-epicatechin supplementation.

BARBARA PIOTRKOWSKI; PAULA D. PRINCE; MARÍA C. LITTERIO; VALERIA CALABRÓ; MARCELA VAZQUEZ-PRIETO; MÓNICA GALLEANO; CESAR G. FRAGA

Valencia

Congreso; OXYGEN CLUB OF CALIFORNIA WORLD CONGRESS; 2015

Nitric oxide synthase (NOS) and NADPH oxidase (NOX) activities are key players in bloodpressure regulation. To evaluate the effect of (?)-epicatechin (EC) on nitric oxide bioavailabilityin rats, we studied NOS and NOX activities in aorta, heart and kidney of fructose-fed rats.Rats were randomly divided in 3 groups depending on beverage and diet consumed: Control (C);Fructose (F:10 % in beverage, 8 wk); Fructose (?)-epicatechin (FEC: 10 % in beverage 20 mg/Kg wb, 8 wk).The treatments did not affect animal?s body weight. Blood pressure (BP) in fructose-fed rats wassignificantly higher while EC-treated rats showed BP values similar to control group.NOS activity in the three tissues was higher in F with respect to C. EC administration increased theactivity to values even higher than in F (p< 0.05). In this line, eNOS activation/phosphorylationwas significantly higher in FEC compared to F. This result may account, in part, for the increaseobserved in NOS activity.NOX activity was significantly higher in F-treated group with respect to C and FEC, in the threetissues studied. This augmented activity was accompanied by higher expression of the activatingsubunit of the NOX-2 isoform, p47phox. Besides, in aorta and heart, NOX-4 was also increased inF compared to the other groups.In conclusion, dietary EC avoid the increase in BP in fructose-fed rats and modulates NObioavailability by increasing NOS activity and expression and/or by diminishing NOX activityand expression.Supported by: ANPCyT PICT 2012-0765, CONICET PIP 20110100752, UBACyT20020130100760 and UBACyT 20020120100177.