植物性雌激素genistein对哇巴因所致豚鼠乳头状肌迟后去极化及触发活动的效应(英文)

Effects of phytoestrogen genistein on delayed afterdepolarization and triggered activity induced by ouabain in guinea pig papillary muscles

应用标准玻璃微电极技术 ,研究了植物性雌激素 genistein (GST)对哇巴因所引起的豚鼠乳头状肌迟后去极化 (DAD)及触发活动 (TA)的效应。结果如下 :(1)预先给予GST (10 ,5 0 ,10 0 μmol/L)剂量依赖性地抑制哇巴因 (1μmol/L)所引起的豚鼠乳头状肌DAD及TA ;(2 )预先应用一氧化氮合酶抑制剂L NAME (1mmol/L) ,不影响GST (5 0 μmol/L)对DAD及TA的效应 ;(3)单独应用 17β 雌二醇 (E2 ,5 μmol/L)或GST (10 μmol/L)对DAD及TA无明显影响 ,而联合应用相同剂量的GST和E2 则产生明显抑制效应。以上结果提示 ,GST可能通过抑制钙离子内流从而具有抗心律失常作用 。

The purpose of this study was to investigate the effects of phytoestrogen genistein (GST) on delayed afterdepolarization (DAD) and triggered activity (TA) induced by ouabain in guinea pig papillary muscles. Action potentials (APs) were recorded from the guinea pig papillary muscles with standard glass microelectrode technique. The results are as follows: (1) DAD and TA induced by ouabain (1 μmol/L) were markedly inhibited by pretreatment with GST (10, 50, 100 μmol/L) in a concentration dependent manner. (2) NG nitro L arginine methyl ester ( L NAME, 1 mmol/L), an NO synthase inhibitor, failed to affect the above effects of GST. (3) 5 μmol/L 17β estradiol (E 2) or 10 μmol/L GST alone showed no effects on DAD and TA, whereas GST combined with E 2 at the same doses exerted significant inhibitory effects on DAD and TA. Since GST is known to reduce the calcium influx, it is suggested that GST might have antiarrhythmic effects, possibly by reducing calcium influx. The antiarrhythmic effects of GST may contribute to its cardioprotective action.