title: Role of gap junction involved with endothelium-derived hyperpolarizing factor for the quercetin-induced vasodilatation in rat mesenteric artery.
abstract: OBJECTIVE
  Modulation of vasodilating actions by quercetin, a kind of flavonoid, was investigated using rat mesenteric arterial ring strips.
  
  
  METHODS
  Ring strips (1mm) of rat mesenteric artery were used. The specimens were kept at 36.5 °C in Krebs-Henseleit solution oxygenated with 95% O(2) and 5% CO(2).
  
  
  RESULTS
  Quercetin (0.1 to 100 μM) dilated the contraction induced by norepinephrine (1 μM) in a concentration-dependent manner. The quercetin-induced vasodilatation was almost resistant to both 100 μM L-N(G)-nitro arginine methyl ester (L-NAME) and 100 μM indomethacin. At 1mM tetraethylammonium (a KCa channel inhibitor) decreased the quercetin-induced vasodilatation, which was resistant to L-NAME and indomethacin, but not significantly. L-NAME- and indomethacin-resistant quercetin-induced vasodilatation was significantly attenuated by 100 μM 18α- and 50 μM 18β-glycyrrhetinic acids (gap junction inhibitors). Endothelium removal as well significantly attenuated the vasodilatation to the same extent.
  
  
  CONCLUSIONS
  These results indicate that quercetin dilates the mesenteric artery via endothelium-dependent mechanisms, and the dilatation is mainly mediated by gap junctions closely involved with endothelium-derived hyperpolarizing factor (EDHF).
authors: Kenseikai Nara Dongo Hospital, Yamatotakada, Nara 635-0022, Japan. drmaro@m4.kcn.ne.jp
authors: Seiichiro
authors: S
authors: Nishida
authors: Hiroyasu
authors: H
authors: Satoh
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D001685:Biological Factors / Q000378:metabolism*; D017629:Gap Junctions / Q000187:drug effects* / Q000378:metabolism; D006034:Glycyrrhetinic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D007213:Indomethacin / Q000494:pharmacology; D008297:Male; D008638:Mesenteric Arteries / Q000187:drug effects* / Q000502:physiology; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009569:Nitric Oxide / Q000378:metabolism; D009638:Norepinephrine / Q000494:pharmacology; D011794:Quercetin / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D014662:Vasoconstrictor Agents / Q000494:pharmacology; D014664:Vasodilation / Q000187:drug effects*; D014665:Vasodilator Agents / Q000494:pharmacology*
chemical_list: D000975:Antioxidants; D001685:Biological Factors; D014662:Vasoconstrictor Agents; D014665:Vasodilator Agents; C067410:endothelium-dependent hyperpolarization factor; C119129:18alpha-glycyrrhetinic acid; D009569:Nitric Oxide; D011794:Quercetin; D006034:Glycyrrhetinic Acid; D019331:NG-Nitroarginine Methyl Ester; D009638:Norepinephrine; D007213:Indomethacin