Dietary flavonoid quercetin stimulates vasorelaxation in aortic vessels

作者：Khoo Nicholas K H^*; White C Roger; Pozzo Miller Lucas; Zhou Fen; Constance Chad; Inoue Takafumi; Patel Rakesh P; Parks Dale A

来源：Free Radical Biology and Medicine, 2010, 49(3): 339-347.

DOI：10.1016/j.freeradbiomed.2010.04.022

• Nitric oxide synthase
• Endothelium
• Cardioprotection
• eNOS
• Heart
• Catalase
• Endothelium-derived hyperpolarizing factor
• Phosphorylation
• Aortic ring segments
• H(2)O(2)
• Fura-2
• Mircofluorometric Ca(2+) imaging

Considerable epidemiological evidence indicates that dietary consumption of moderate levels of polyphenols decreases both the incidence of cardiovascular disease and the mortality associated with myocardial infarction. Molecular mechanisms of this cardiovascular protection remain uncertain but can involve changes in rates of nitric oxide (NO) generation by endothelial nitric oxide synthase (eNOS). We examined the vascular responses to quercetin using a combination of biochemical and vessel function criteria. Quercetin treatment for 30 min enhanced relaxation of rat aortic ring segments. Moreover, the addition of L-NAME (100 mu M) or charybdotoxin (ChTx) blocked quercetin-mediated vasorelaxation thus demonstrating the effect was partially dependent on NOS and endothelium-derived hyperpolarizing factor (EDHF). Additionally, bovine aortic endothelial cells (BAEC) treated with quercetin showed a rapid increase of intracellular Ca(2+) concentrations as well as a dose- and time-dependent stimulation of eNOS phosphorylation with a concomitant increase in NO production. These results demonstrate that quercetin-mediated stimulation of eNOS phosphorylation increases NO bioavailability in endothelial cells and can thus play a role in the vascular protective effects associated with improved endothelial cell function.

• 出版日期2010-8-1