In the guniea-pig mesenteric artery, E614 (less than 10(-6) g/ml) did not modify the membrane potential and resistance, but did suppress the spike evoked by outward current pulses in the presence of 3-5 mM TEA. This agent also suppressed the K-induced and noradrenaline-induced contractions. 2. In the mesenteric artery, E614 suppressed the amplitude of e.j.ps evoked by perivascular nerve stimulation. However, the facilitation process produced by repetitive stimulation was less affected. Miniature e.j.ps generated in the presence of 3 mM TEA were also suppressed by E614. 3. In the porcine coronary artery, E614 had little effect on the spike evoked by outward current pulses, in the presence of TEA. The mechanical response evoked by acetylcholine, excess [K]0 or electrical depolarization was hardly affected. 4. When the action of E614 was compared with that of diltiazem, a Ca channel blocker, this agent possesses properties which produce vasodilation of the peripheral vascular bed and thus may be considered as a hypotensive agent.
摘要
在豚鼠肠系膜动脉中，E614（低于10⁻⁶ g/ml）不改变膜电位和电阻，但在存在3 - 5 mM四乙铵（TEA）的情况下能抑制外向电流脉冲诱发的动作电位。该药物还能抑制钾离子诱导的和去甲肾上腺素诱导的收缩。2. 在肠系膜动脉中，E614抑制血管周围神经刺激诱发的兴奋性接头后电位（e.j.ps）的幅度。然而，重复刺激产生的易化过程受影响较小。在存在3 mM TEA的情况下产生的微小e.j.ps也被E614抑制。3. 在猪冠状动脉中，在存在TEA的情况下，E614对外向电流脉冲诱发的动作电位影响很小。乙酰胆碱、细胞外高钾（[K]₀过量）或电去极化诱发的机械反应几乎不受影响。4. 当将E614的作用与钙通道阻滞剂地尔硫䓬的作用进行比较时，该药物具有使外周血管床血管舒张的特性，因此可被视为一种降压药。
