title: Vasorelaxant effect of Prunus yedoensis bark.
abstract: BACKGROUND
  Prunus yedoensis Matsum. is used as traditional medicine-'Yaeng-Pi' or 'Hua-Pi'-in Japan and Korea. However, no studies have examined the pharmacological activities of the P. yedoensis bark. Only the antioxidant and antiviral activities of P. yedoensis fruit and the anti-hyperglycaemic effect of P. yedoensis leaf have been investigated. While studying the antihypertensive effects of several medicinal plants, we found that a methanol extract of P. yedoensis bark (MEPY) had distinct vasorelaxant effects on rat aortic rings.
  
  
  METHODS
  The aortic rings were removed from Sprague-Dawley rats and suspended in organ chambers containing 10 ml Krebs-Henseleit solution. The aortic rings were placed between 2 tungsten stirrups and connected to an isometric force transducer. Changes in tension were recorded via isometric transducers connected to a data acquisition system.
  
  
  RESULTS
  MEPY relaxed the contraction induced by phenylephrine (PE) both in endothelium-intact and endothelium-denuded aortic rings concentration dependently. However, the vasorelaxant effects of MEPY on endothelium-denuded aortic rings were lower than endothelium-intact aortic rings. The vasorelaxant effects of MEPY on endothelium-intact aortic rings were reduced by pre-treatment with L-NAME, methylene blue, or ODQ. However, pre-treatment with indomethacin, atropine, glibenclamide, tetraethylammonium, or 4-aminopyridine had no affection. In addition, MEPY inhibited the contraction induced by extracellular Ca(2+) in endothelium-denuded rat thoracic aorta rings pre-contracted by PE (1 μM) or KCl (60 mM) in Ca(2+)-free solution.
  
  
  CONCLUSIONS
  Our results suggest that MEPY exerts its vasorelaxant effects via the activation of NO formation by means of L-Arg and NO-cGMP pathways and via the blockage of extracellular Ca(2+) channels.
authors: Department of Herbology, College of Korean Medicine, Kyung Hee University, 1 Hoegi-Dong, Dongdaemun-Gu, 130-701 Seoul, Republic of Korea.
authors: Kyungjin
authors: K
authors: Lee
authors: Inhye
authors: I
authors: Ham
authors: Gabsik
authors: G
authors: Yang
authors: Mihwa
authors: M
authors: Lee
authors: Youngmin
authors: Y
authors: Bu
authors: Hocheol
authors: H
authors: Kim
authors: Ho-Young
authors: HY
authors: Choi
mesh_terms: D000818:Animals; D001011:Aorta / Q000187:drug effects; D001120:Arginine / Q000378:metabolism; D002118:Calcium / Q000378:metabolism* / Q000494:pharmacology; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D015220:Calcium Channels / Q000187:drug effects; D006152:Cyclic GMP / Q000378:metabolism; D004730:Endothelium, Vascular / Q000187:drug effects; D008751:Methylene Blue; D019331:NG-Nitroarginine Methyl Ester; D009569:Nitric Oxide / Q000096:biosynthesis; D010656:Phenylephrine; D024301:Plant Bark; D010936:Plant Extracts / Q000494:pharmacology*; D027861:Prunus; D051381:Rats; D017207:Rats, Sprague-Dawley; D014661:Vasoconstriction / Q000187:drug effects*; D014665:Vasodilator Agents / Q000494:pharmacology*
chemical_list: D002121:Calcium Channel Blockers; D015220:Calcium Channels; D010936:Plant Extracts; D014665:Vasodilator Agents; D010656:Phenylephrine; D009569:Nitric Oxide; D001120:Arginine; D006152:Cyclic GMP; D002118:Calcium; D008751:Methylene Blue; D019331:NG-Nitroarginine Methyl Ester