title: Vascular relaxation by the methanol extract of Sorbus cortex via NO-cGMP pathway.
abstract: The methanol extract of Sorbus commixta cortex (MSC) induced relaxation of the phenylephrine-precontracted aorta in a dose-dependent manner, which was disappeared by removal of functional endothelium. Pretreatment of the aortic tissues with N(G)-nitro-L-arginine methyl ester (L-NAME), methylene blue, or 1H-[1,2,4]-oxadiazole-[4,3-alpha]-quinoxalin-1-one (ODQ) inhibited the vascular relaxation induced by MSC. MSC-induced vascular relaxations were also markedly attenuated by addition of verapamil or diltiazem, while the relaxant effect of MSC was not blocked by pretreatment with indomethacine, glibenclamide, tetraethylammonium (TEA), atropine, or propranolol, respectively. Incubation of endothelium-intact carotid arteries or of human umbilical vein endothelial cells (HUVECs) with MSC increased the production of guanosine 3',5'-cyclic monophosphate (cGMP). Moreover, MSC-induced cGMP production was effect was blocked by pretreatment with L-NAME or ODQ. These results suggest that MSC dilates vascular smooth muscle via endothelium-dependent nitric oxide-cGMP signaling pathway, possible involvement of L-type Ca(2+) channel.
authors.affiliation: Department of Herbal Resources, Professional Graduate School of Oriental Medicine, Wonkwang University, Jeonbuk 570-749, Republic of Korea.
authors.forename: Dae Gill
authors.initials: DG
authors.lastname: Kang
authors.forename: Jun Kyoung
authors.initials: JK
authors.lastname: Lee
authors.forename: Deok Ho
authors.initials: DH
authors.lastname: Choi
authors.forename: Eun Jin
authors.initials: EJ
authors.lastname: Sohn
authors.forename: Mi Kyoung
authors.initials: MK
authors.lastname: Moon
authors.forename: Ho Sub
authors.initials: HS
authors.lastname: Lee
mesh_terms: D000818:Animals; D001011:Aorta / Q000187:drug effects / Q000378:metabolism; D006152:Cyclic GMP / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D066298:In Vitro Techniques; D008297:Male; D000432:Methanol / Q000494:pharmacology; D009569:Nitric Oxide / Q000378:metabolism*; D010936:Plant Extracts / Q000302:isolation & purification / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology; D031994:Sorbus; D014664:Vasodilation / Q000187:drug effects* / Q000502:physiology
chemical_list: D010936:Plant Extracts; D009569:Nitric Oxide; D006152:Cyclic GMP; D000432:Methanol