Grape Juice Causes Endothelium-Dependent Relaxation via a Redox-Sensitive Src- And Akt-dependent Activation of eNOS

Cardiovasc Res. 2007 Jan 15;73(2):404-13. doi: 10.1016/j.cardiores.2006.08.004. Epub 2006 Aug 8.

Abstract

Objectives: 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.

MeSH terms

  • Animals
  • Beverages
  • Blotting, Western / methods
  • Coronary Vessels*
  • Endothelium, Vascular / drug effects
  • Endothelium, Vascular / metabolism*
  • Enzyme Activation
  • In Vitro Techniques
  • Nitric Oxide / analysis
  • Nitric Oxide / metabolism
  • Nitric Oxide Synthase Type III / metabolism*
  • Oxidation-Reduction
  • Phosphorylation
  • Plant Extracts / pharmacology
  • Protein-Serine-Threonine Kinases / metabolism*
  • Proto-Oncogene Proteins c-akt / metabolism
  • Proto-Oncogene Proteins pp60(c-src) / metabolism
  • Superoxides / analysis
  • Superoxides / metabolism
  • Swine
  • Vasodilation / drug effects*
  • Vitis*

Substances

  • Plant Extracts
  • Superoxides
  • Nitric Oxide
  • NOS3 protein, human
  • Nitric Oxide Synthase Type III
  • Proto-Oncogene Proteins pp60(c-src)
  • Protein-Serine-Threonine Kinases
  • Proto-Oncogene Proteins c-akt