雌二醇和孕酮对家兔右心室乳头肌动作电位的影响

目的探讨雌二醇和孕酮对家兔右心室乳头肌动作电位时程（action potential duration，APD）的影响及其与浓度和刺激频率的关系。方法利用玻璃微电极技术记录家兔右心室乳头肌动作电位，观察不同浓度雌二醇和孕酮对家兔右心室乳头肌APD的影响及其与刺激频率的关系。结果在1～30μmol／L的浓度范围内，雌二醇浓度依赖性的延长家兔右心室乳头肌APD，而孕酮则浓度依赖性的缩短APD：雌二醇（3μmol／L）对APD的延长作用随刺激频率增大而减弱，而孕酮（10μmol／L）对APD的缩短作用则随频率的增大而增强。结论雌二醇和孕酮对家兔右心室乳头肌APD有着不同的作用，且此种影响具有刺激频率依赖性。

Effects of estradiol and progesterone on action potential in papillary muscles of rabbit right ventricles

Objective To investigate the effects of estradiol and progesterone on action potential duration（ APD ） in papillary muscles of right ventricles in rabbits. Methods Action potential in papillary muscles of rabbit right ventricles was recorded by the glass microelectrode technique, and the relationship between the effects of estradiol and progesterone on APD at different concentrations in papillary muscles of rabbit right ventricles and stimulation frequency were observed. Results Estradiol （1-30μmol · L^- 1） dose-dependently prolonged APD of rabbit right ventricular papillary muscles, whereas progesterone （ 1 - 30 μmol · L^- 1 ） dose-dependently shortened APD. The prolongation of APD by estradiol（3 μmol · L^- 1 ） was weakened and the shortening of APD by progesterone（ 10 μmol · L^- 1 ） was enhanced when stimulus frequencies were increased. Conclusion Estradiol and progesterone have different effects on APD of right ventricular papillary muscle in rabbit.