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目的：研究雌二醇（Ｅｓｔ）、睾酮（Ｔｅｓ）和孕酮（Ｐｒｏ）对豚鼠心室乳头状肌动作电位（ＡＰ）和收缩活动的影响．方法：经典的玻璃微电极方法和心肌收缩描记方法．结果：Ｅｓｔ在较低浓度（１μｍｏｌ·Ｌ－１）即明显减慢动作电位０期最大除极速率（Ｖｍａｘ）．随着浓度增加，还可延长动作电位时程（ＡＰＤ５０，ＡＰＤ９０）和有效不应期（ＥＲＰ）．并呈现负性肌力作用，使最大收缩张力（Ｐｍａｘ）降低，张力产生速率（ｄＴ／ｄｔ）减慢．Ｔｅｓ在较高浓度（１００μｍｏｌ·Ｌ－１－１ｍｍｏｌ·Ｌ－１）可延长ＡＰＤ９０、ＥＲＰ，降低Ｐｍａｘ和ｄＴ／ｄｔ．而Ｐｒｏ对心肌电生理活动及收缩均无明显影响．结论：雌激素延长豚鼠乳头状肌动作电位，抑制其收缩活动．
Objective: To study the effects of estradiol, testosterone and progesterone on the action potential (AP) and contractile activity of guinea pig ventricular papillary muscles. Methods: Classic glass microelectrode method and myocardial contractile method. Results: Est at the lower concentration (1μmol·L-1) significantly slowed down the maximal depolarization rate (Vmax) of action potential in phase 0. With increasing concentrations, action potential duration (APD50, APD90) and effective refractory period (ERP) can be extended. And showed negative inotropic effect, so that the maximum contraction tension (Pmax) decreased, tension generation rate (dT / dt) slowed. Tes increased APD90, ERP and decreased Pmax and dT / dt at higher concentration (100μmol·L-1-1mmol·L-1). Pro had no significant effect on electrophysiological activity and contraction of myocardium. Conclusion: Estrogen prolongs the action potentials of guinea pig papillary muscles and inhibits their contractile activity.