Vasodilatation Produced by Orientin and Its Mechanism Study

• Fu Xiao-Chun

  Department of Pharmacology, Shenyang Pharmaceutical University

• Wang Min-Wei

  Department of Pharmacology, Shenyang Pharmaceutical University

• Li Shao-Peng

  Department of Brain Neurosurgery, China Medical University

• Zhang Ying

  College of Biosystem Engineering and Food Science, Zhejiang University

• Wang Huai-Liang

  Department of Clinical Pharmacology, China Medical University

抄録

In this paper we investigated the vascular activity and possible mechanism of Orientin, from bamboo leaves (Phyllostachys nigra), in isolated thoracic aortic rings from New Zealand rabbit. Among the four compounds, studied, only Orientin relaxed phenylephrine-induced contractions with an IC₅₀ value of 2.28 μM in the endothelium intact and with an IC₅₀ value around 7.27 μM in the endothelium removed aortic rings. The vasorelaxant effect of Orientin on endothelium-intact thoracic aortic rings was attenuated by the nitric oxide (NO) synthase inhibitor N^G-nitro-L-arginine methyl ester, but not by indomethacin (a cyclooxygenase inhibitor), tetraethylammonium chloride (K⁺ channels inhibitor) or propranolol (β-receptor inhibitor). Furthermore, Orientin inhibited norepinephrine (NE), CaCl₂ and KCl-induced vasoconstriction concentration dependently in a non-competitive manner, and also reduced both the initial fast release and the sustained phases of phenylephrine-induced contractions. Orientin can stimulate NO production from endothelial cells. Orientin also increased cyclic guanosine 3,5-cyclic monophosphate (cGMP) levels without changes in adenosine-3′,5′-cyclic phosphoric acid (cAMP) in rabbit aorta. The results showed that Orientin relaxed thoracic aortic rings by the nitric oxide-cGMP pathway, and in the vascular smooth muscle inhibited the contraction induced by the activation of receptor-operating and voltage-dependent Ca²⁺ channels. Cyclooxygenase pathway, potassium channels, β-receptors and cAMP pathway, on the other hand, had no apparent roles. The inhibition of both intracellular Ca²⁺ release and extracellular Ca²⁺ influx may be one of the main vasorelaxant mechanisms of Orientin.

収録刊行物

• Ｂｉｏｌｏｇｉｃａｌ　＆　Ｐｈａｒｍａｃｅｕｔｉｃａｌ　Ｂｕｌｌｅｔｉｎ

  Ｂｉｏｌｏｇｉｃａｌ　＆　Ｐｈａｒｍａｃｅｕｔｉｃａｌ　Ｂｕｌｌｅｔｉｎ 28 (1), 37-41, 2005

  公益社団法人 日本薬学会

キーワード

• orientin
• vasorelaxant
• endothelium
• nitric oxide (NO)
• rabbit thoracic aorta
• cyclic nucleotide

詳細情報

• CRID: 1390282679604523008
• NII論文ID: 110003665767
• NII書誌ID: AA10885497
• DOI: 10.1248/bpb.28.37
• ISSN: 13475215
• ISSN: 09186158
• NDL書誌ID: 7200933
• PubMed: 15635160
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I7200933
• Web Site: http://www.jstage.jst.go.jp/article/bpb/28/1/28_1_37/_pdf
• Web Site: https://search.jamas.or.jp/link/ui/2006233309
• 本文言語コード: en
• データソース種別:
  • JaLC
  • NDL
  • Crossref
  • PubMed
  • CiNii Articles
• 抄録ライセンスフラグ: 使用不可