• 대한한의학방제학회지
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• 제17권2호
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• pp.175-186
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• 2009

The vasorelaxant effect of an extract of Lophatherum gracile Brongn (ELB) and its possible action mechanism were ascertained in aortic tissues isolated from rats. ELB relaxed endothelium-intact thoracic aorta in a dose-dependent manner. However, the induced vascular relaxation was abolished by removal in endothelium of the thoracic aorta. Pretreatment of endothelium-intact vascular tissues with $N^G$-nitro-L-arginine methyl ester (L-NAME) or 1H-[1,2,4]-oxadiazole-[4,3-$\alpha$]-quinoxalin-1-one (ODQ) significantly inhibited vascular relaxation induced by ELB. Moreover, ELB significantly increased cGMP production in aortic tissues, which was blocked by pretreatment with L-NAME or ODQ. The vasorelaxant effect of ELB was attenuated by tetraethylammonium (TEA), and glibenclamide. ELB-induced vasorelaxation was not blocked by atropine, propranolol, indomethacin, verapamil, and diltiazem. Taken together, the present study demonstrates that ELB dilates vascular smooth muscle via an endothelium-dependent NO-cGMP signaling pathway, which may be at least in part related with the function of $K^+$ channels.