IBIMOL   23987
INSTITUTO DE BIOQUIMICA Y MEDICINA MOLECULAR PROFESOR ALBERTO BOVERIS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
(-)-Epicatechin prevents oxidative modifications in the heart of L-NAME-treated rats
Autor/es:
M. GALLEANO; V. CALABRO; B. PIOTRKOWSKI; BARRIOS, M.; C. G. FRAGA
Lugar:
Sietges
Reunión:
Congreso; V International Conference Polyphenols and Health; 2011
Institución organizadora:
V International Conference Polyphenols and Health
Resumen:
Modifications in dietary habits may be a valid strategy to prevent hypertension and its secondary effects. The aim of this study was to evaluate factors that may contribute to oxidative stress in the myocardium during the initial stages of hypertension induced by L-NAME treatment, and its modulation by (-)-epicatechin (EC). Sprague-Dawley rats were divided into 3 groups: Control (C), L-NAME (L: 360 mg/L), L-NAME + epicatechin (L+EC: 360 mg/L + 0.4 mg/g diet). L (drinking water) and EC (solid diet) were administered for 4 d. Animals were sacrificed and hearts were excised. Blood pressure in L group was significantly higher (p<0.05) than in C and L+EC. Heart/body weight ratio was similar in the 3 groups. NADPH oxidase-dependent superoxide production (determined by lucigenin assay) was significantly increased in L with respect to C, and L+EC (C:1.0±0.1; L:1.4±0.1; L+Epi:0.9±0.1 cpm/mg protein; p<0.05 L vs. C and vs. L+EC). This increase was not associated with a higher expression of p47phox NADPH oxidse subunit. Total SOD activity was not modified by the treatments, but Mn-SOD activity in L and L+EC was significantly lower than in C (C:2.9±0.4; L:1.9±0.2; L+EC:2.1±0.3 U MnSOD/mg protein) (p<0.05 vs C). Mn-SOD expression was lower in L than in C and L+EC). There was no significant change in catalase activity but glutathione peroxidase activity was higher in L compared to C and L+EC. In summary, in the initial stages of hypertension, oxidant production may be increased in cardiac tissue, possibly related to both, a higher NADPH-oxidase activity and a lower Mn-SOD activity. Dietary EC prevented the effects associated with L treatment in the heart, and this effect could be interpreted as a protection from the increased oxidant production related to hypertension.