四氢巴马汀抗异丙肾上腺素诱发的室性心律失常作用

Suppression effects of L-tetrahydropalmatine on ventricular arrhythmias induced by isoprenaline

目的探讨左旋-四氢巴马汀(L-THP)抗室性心律失常(VA)的作用及机制。方法采用跨室壁单向动作电位记录技术研究L-THP对犬在体三层心肌动作电位时程(APD90)、有效不应期(ERP)和跨室壁复极离散度(TDR)的影响;通过心肌局部给予异丙肾上腺素(Iso)模拟突发交感神经张力增加,观察L-THP对程序电刺激(PES)所致的VA发生率和诱发VA所需的最低Iso浓度的影响。结果L-THP延长三层心肌的APD90和ERP但减少TDR[(18.78±3.19)msvs(10.78±2.11)ms,P<0.01];降低PES对VA的诱发率(21.61%vs6.17%,χ2=14.864 5,P<0.005);增加诱发VA所需要的最低Iso浓度(4.64×10-6mg/mlvs3.59×10-3mg/ml,P<0.001);抑制局部Iso诱发的早期后除极和触发活动所引起的VA。结论L-THP有显著的抗VA作用,是一种有望成为抗VA的中药。

Objective To investigate anti-ventricular arrhythmia （VA） effects and mechanism of L-tetrahydropalmatine （L-THP）. Methods Transmural monophasic action potential （MAP） recording technique was adopted to explore the effects of L-THP on action potential duration （APD90）, effective refractory period （ERP） and transmural dispersion of repolarization （TDR） in canine myocardium in vivo. Upregulation of sympathetic tone was mimicked by locally administration of isoprenaline （Iso） on myocardium. Effects of L-THP on VA occurrence ratio triggered by PES and on minimum concentration of Iso needed to induce VA were observed. Results L-THPprolongedAPDg0andERPwhiledecreasedTDR[（18.78±3.19）ms vs （10.78±2.11）ms,P〈0.01] significantly. VA occurrence ratio（21.61%vs 6.17 % ,χ^2 = 14. 864 5, P〈 0. 005） induced by PES is decreased, and the minimum concentration of Iso [ （4.64 × 10^ - 6 ） mg/ml vs （3.59 × 10^- 3 ） mg/ml, P 〈 0.001 ] needed to induce VA was increased remarkably by administration of L-THP. L-THP also had significant effects on inhibition of VA triggered by early post-depolarization induced by locally administration of Iso and trigger activity. Conclusion L-THP shows significant anti-ventricular arrhythmias activity, which therefore may provide a new kind of anti-ventricular arrhythmia approach.