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目的旨在探讨药物阻断L型钙电流与其缩短心肌细胞动作电位时程（APD）效应之间的相互关系。方法采用膜片钳全细胞式记录方法，同时观察了丹参酮Ⅱ-A（DST）对豚鼠同一个心室肌细胞跨膜电位和L型钙电流的影响，并对药物的有关效应作相关分析。结果DST显著缩短豚鼠心肌单细胞的动作电位时程（APD），呈剂量依赖关系（r=-0.987）;10、20、和40μmol·L-1DST可使L型钙内向峰电流分别减少35.2％、57.7％和74.7％，亦呈浓度依赖方式（r=-0.948）。经相关性分析证实，在本实验采用的DST相应浓度作用下，APDS50、APD90和APD50～10的缩短与L型钙电流峰值的减少之间呈高度正相关（r分别为0.9870、0.9867和0.9896）。结论DST缩短心肌细胞APD和阻断L型钙电流的效应是高度一致的，且以APD50～10表示平台期的长短更合理。
The aim of this study was to investigate the interrelationship between drug blocking L-type calcium current and its effect on shortening cardiomyocyte action potential duration (APD). Methods The patch clamp whole cell recording method was used to observe the effect of tanshinone Ⅱ-A (DST) on the transmembrane potential and L-type calcium current in the same ventricular myocytes of guinea pigs. The related effects of drugs were also analyzed. Results DST significantly shortened the action potential duration (APD) of single cells in guinea pigs in a dose-dependent manner (r = -0.987). The in-peak peak currents of L-type calcium decreased by 35.2% at 10,20 and 40μmol·L- , 57.7% and 74.7%, respectively, also in a concentration-dependent manner (r = -0.948). Correlation analysis confirmed that the shortening of APDS50, APD90 and APD50 ~ 10 and the decrease of L-type calcium current were positively correlated (r = 0.9870, 0.9867 and 0.9896, respectively) under the corresponding concentration of DST used in this experiment. . Conclusions The effect of DST shortening the APD of cardiomyocytes and blocking the L-type calcium current is highly consistent, and the plateau period of APD50-10 is more reasonable.