雌二醇对豚鼠心室乳头肌细胞动作电位的影响

Effects of 17 β Estradiol on Action Potential in Guinea Pig Papillary Muscles

目的：观察雌二醇（１７βｅｓｔｒａｄｉｏｌ，简称 Ｅ）对心室肌细胞动作电位的影响。方法：采用常规微电极技术记录豚鼠心室乳头肌细胞在不同 Ｅ浓度和作用时间的动作电位。结果：（１）较高浓度 Ｅ（３×１０－ ５ ｍ ｏｌ／ Ｌ、１×１０－ ４ｍ ｏｌ／ Ｌ）使豚鼠心室乳头肌细胞动作电位时程 Ａ Ｐ Ｄ２０、 Ａ Ｐ Ｄ５０、 Ａ Ｐ Ｄ９０ 和 Ａ Ｐ Ｄ 全程均延长 ，其中以 Ａ Ｐ Ｄ９０和 Ａ Ｐ Ｄ 全程的延长最为显著。结论：

Objective: To investigate the effects of 17 β estradiol (E) on action potential (AP) of cardiac muscles. Methods: To investigate the effects of 17 β estradiol (E) on action potential (AP) of cardiac muscles. Methods:Methods: It was studied with microelectrode technique to record the changs of AP at 10,40,60,80,100 and 120 minutes after administraltion of E. Results: E induced prolongations of AP duration in concentration dependent and time dependent manners. E (30μmol/L and 100μmol/L) significantly prolonged APDs(APD 20 ,APD 50 ,APD 90 and APD),especially APD 90 and APD (P<0.01), Conclusions: The results show that E prolongs the 2nd and 3rd phases of repolarization,suggesting that E inhibits K + channels in guinea pig papillary muscles.