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目的通过比较白花前胡甲素（Pd－Ia）与异丙肾上腺素对豚鼠单一心室肌细胞迟发性外向钾电流（IK）的影响，初步探讨Pd－Ia开放钾通道作用的可能机制。方法；应用全细胞膜片钳制技术。结果与结论：Pd－Ia对IK通道作用的最大效应与异丙肾上腺素相近，均使IK增加2～2．5倍，对IK的激活动力学过程均无明显影响，而且两药的作用不具有相加性。另外，乙酰胆碱对Pd－Ia增加IK作用的影响也与对异丙肾上腺素的影响相似，提示Pd－Ia对IK的作用可能是通过激活PKA而产生的。其确切机制还有待进一步实验研究。
Objective To compare the effects of Pd-Ia and isoproterenol on delayed outward potassium current (IK) in guinea pig ventricular myocytes, and to explore the possible mechanism of Pd-Ia potassium channel opening. Method; Whole cell patch clamp technique applied. RESULTS AND CONCLUSION: The maximal effect of Pd-Ia on IK channel was similar to that of isoproterenol, which increased the IK by 2 to 2.5 times. There was no significant effect on the activation kinetics of IK, and the effect of both drugs was not. Additive. In addition, the effect of acetylcholine on the increase of IK in Pd-Ia is similar to that of isoproterenol, suggesting that the effect of Pd-Ia on IK may be through the activation of PKA. The exact mechanism remains to be further experimental research.