Medical College of Shantou University, No.22 Xinling Road, Shantou, Guangdong, 515041, People's Republic of China.
Naunyn Schmiedebergs Arch Pharmacol. 2009 Jun;379(6):587-97. doi: 10.1007/s00210-008-0388-2. Epub 2009 Feb 4.
Puerarin, a major isoflavonoid compound from the Chinese herb, Ge-gen (Pueraria lobata), has effective treatment on myocardial and cerebral ischemia, glaucoma and sudden deafness in clinical setting in China. Our present work showed that puerarin (50, 150, 450 microM) concentration-dependently inhibited phenylephrine or KCl-induced contraction only in endothelium-intact rat aortic rings. In Ca(2+)-free solution, the antivasoconstriction of puerarin on phenylephrine was totally deprived. N (G)-nitro-L-arginine methyl ester, 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one, indomethacin and the three K(+) channel blockers, glibenclamide, tetraethylammonium and Ba(2+) displayed significant inhibitory effects on the antivasoconstriction of puerarin. 8-bromo-cGMP significantly strengthened the action of puerarin. Puerarin (10-160 microM) concentration-dependently induced the NO production in the rat aortic cells. These findings suggested that the antivasoconstriction elicited by puerarin is endothelium-dependent. NO/NO-cGMP pathway, PGI(2) and the opening of K(+) channels sensitive to glibenclamide, tetraethylammonium, and Ba(2+), which might be triggered by the extracellular Ca(2+) influx in the endothelium, appear to contribute to the antivasoconstriction of puerarin.
葛根素是中国草药葛根中的一种主要异黄酮化合物，在中国临床上对心肌和脑缺血、青光眼和突发性耳聋有有效治疗作用。我们目前的工作表明，葛根素（50、150、450μM）浓度依赖性地抑制去氧肾上腺素或 KCl 诱导的血管收缩，仅在血管内皮完整的大鼠主动脉环中。在无钙溶液中，葛根素对去氧肾上腺素的抗血管收缩作用完全丧失。N（G）-硝基-L-精氨酸甲酯、1H-[1,2,4]恶二唑[4,3-a]喹喔啉-1-酮、吲哚美辛和三种 K（+）通道阻滞剂格列本脲、四乙铵和 Ba（2+）对葛根素的抗血管收缩作用均有显著抑制作用。8-溴-cGMP 显著增强了葛根素的作用。葛根素（10-160μM）浓度依赖性地诱导大鼠主动脉细胞中 NO 的产生。这些发现表明，葛根素引起的血管收缩是内皮依赖性的。NO/NO-cGMP 途径、PGI2 和对格列本脲、四乙铵和 Ba（2+）敏感的 K（+）通道的开放，可能是由内皮细胞外 Ca（2+）内流触发的，这可能有助于葛根素的抗血管收缩作用。
