Kuromaru O, Sakai K
Arch Int Pharmacodyn Ther. 1986 Oct;283(2):272-81.
Effects of 2 antianginal agents, nicorandil and nitroglycerin, on the rhythmic contraction induced by 3,4-diaminopyridine (DAP) were investigated in the isolated coronary artery of the miniature pig. Application of 10(-2) M 3,4-DAP elicited a sustained rhythmic contraction of the artery, lasting more than 3 hr. Nicorandil significantly reduced the peak tension of the contraction phase and the tension of the relaxation phase at concentrations of 10(-6) and 10(-5) M. The cycle length and the reappearance time of the rhythmic contraction were only significantly prolonged at a concentration of 10(-5) M. Finally a concentration of 10(-4) M led to the disappearance of rhythmic contraction. Nitroglycerin (10(-8) - 10(-4) M) significantly reduced the peak tension of the contraction phase and the tension during the relaxation phase in a concentration-dependent manner. At concentrations of 10(-6) to 10(-4) M, it also greatly prolonged the reappearance time of the rhythmic contraction, but the contraction was never eliminated even at the highest concentration (10(-4) M) of nitroglycerin used. The result indicates that nicorandil has an effect on the rhythmic contraction caused by 3,4-DAP through a mechanism somewhat different from nitroglycerin.
在小型猪的离体冠状动脉中，研究了两种抗心绞痛药物尼可地尔和硝酸甘油对3,4 - 二氨基吡啶（DAP）诱导的节律性收缩的影响。应用10⁻² M的3,4 - DAP可引起动脉持续的节律性收缩，持续时间超过3小时。尼可地尔在10⁻⁶和10⁻⁵ M浓度时，可显著降低收缩期的峰值张力和舒张期的张力。仅在10⁻⁵ M浓度时，节律性收缩的周期长度和再次出现时间才显著延长。最后，10⁻⁴ M的浓度导致节律性收缩消失。硝酸甘油（10⁻⁸ - 10⁻⁴ M）以浓度依赖的方式显著降低收缩期的峰值张力和舒张期的张力。在10⁻⁶至10⁻⁴ M浓度时，它还极大地延长了节律性收缩的再次出现时间，但即使在所用硝酸甘油的最高浓度（10⁻⁴ M）下，收缩也从未消除。结果表明，尼可地尔对3,4 - DAP引起的节律性收缩的作用机制与硝酸甘油有所不同。
