Grape juice causes endothelium-dependent relaxation via a redox-sensitive Src- and Akt-dependent activation of eNOS.
OBJECTIVE
An enhanced endothelial formation of nitric oxide (NO) and endothelium-derived hyperpolarizing factor (EDHF), is thought to contribute to the protective effect of moderate consumption of red wine on coronary diseases. The present study has characterized endothelium-dependent relaxations to Concord grape juice (CGJ), a non-alcoholic rich source of grape-derived polyphenols, in the coronary artery.


METHODS
Porcine coronary artery rings were suspended in organ chambers for the measurement of changes in isometric tension in the presence of indomethacin. NO formation was assessed by electron spin resonance spectroscopy, and the phosphorylation of Src, Akt and endothelial NO synthase (eNOS) by Western blot analysis in cultured endothelial cells.


RESULTS
Endothelium-dependent relaxations to CGJ were slightly but significantly reduced by L-NA, not affected by charybdotoxin (CTX) plus apamin (APA, two inhibitors of EDHF-mediated responses) whereas the combination of L-NA, CTX plus APA reduced maximal relaxation to about 50%. In the presence of CTX plus APA, relaxations to CGJ were markedly reduced by the membrane permeant mimetic of superoxide dismutase (SOD), MnTMPyP, the membrane permeant analogue of catalase polyethyleneglycol-catalase (PEG-catalase), PP2, an inhibitor of Src kinase, and by wortmannin, an inhibitor of the PI3-kinase. CGJ stimulated the formation of reactive oxygen species and the N(omega)-nitro-L-arginine-, PP2- and wortmannin-sensitive formation of NO in endothelial cells. The formation of NO was associated with a redox-sensitive and time-dependent phosphorylation of Src, Akt and eNOS.


CONCLUSIONS
CGJ induces endothelium-dependent relaxations of coronary arteries, which involve a NO-mediated component and also, to a minor extent, an EDHF-mediated component. In addition, CGJ-induced NO formation is due to the redox-sensitive activation of Src kinase with the subsequent PI3-kinase/Akt-dependent phosphorylation of eNOS.
Anselm
Eric
E
Département de Pharmacologie et Physico-Chimie, UMR 7175-LC1, Université Louis Pasteur de Strasbourg, 74 route du Rhin, F-67401 Illkirch, France. valerie.schini-kerth@pharma-u.strasbg.fr
Chataigneau
Marta
M
Ndiaye
Mamadou
M
Chataigneau
Thierry
T
Schini-Kerth
Valérie B
VB
D000818:Animals; D001628:Beverages; D015153:Blotting, Western / Q000379:methods; D003331:Coronary Vessels; D004730:Endothelium, Vascular / Q000187:drug effects / Q000378:metabolism*; D004789:Enzyme Activation; D066298:In Vitro Techniques; D009569:Nitric Oxide / Q000032:analysis / Q000378:metabolism; D052250:Nitric Oxide Synthase Type III / Q000378:metabolism*; D010084:Oxidation-Reduction; D010766:Phosphorylation; D010936:Plant Extracts / Q000494:pharmacology; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D016392:Proto-Oncogene Proteins pp60(c-src) / Q000378:metabolism; D013481:Superoxides / Q000032:analysis / Q000378:metabolism; D013552:Swine; D014664:Vasodilation / Q000187:drug effects*; D027843:Vitis
D010936:Plant Extracts; D013481:Superoxides; D009569:Nitric Oxide; C496314:NOS3 protein, human; D052250:Nitric Oxide Synthase Type III; D016392:Proto-Oncogene Proteins pp60(c-src); D017346:Protein Serine-Threonine Kinases; D051057:Proto-Oncogene Proteins c-akt