麝香保心丸对急性心肌梗死大鼠梗死边缘带心肌中IL-18时间差异性表达与室性心律失常的影响

目的 探讨麝香保心丸对急性心肌梗死后室性心律失常的抑制作用及机制.方法 90只雄性急性心肌梗死大鼠随机分为麝香保心丸高、低剂量(45.0、22.5 mg/kg)组及模型组,每组30只,每组大鼠再均分为第1、2周末2个亚组,每组15只.另取20只大鼠作为假手术组,均分为第1、2周末2个亚组,每组10只.麝香保心丸组第1、2周末2个亚组分别于术后第2天起ig给药1、2周,假手术组和模型组给予等量生理盐水.第1、2周末时以程序电刺激诱发各组大鼠室性心律失常后,假手术组取位于左心室游离壁心肌组织,心肌梗死各组取位于左心室梗死边缘带心肌组织,检测白细胞介素-18(IL-18)表达.结果 第1、2周末时模型组大鼠梗死边缘带心肌组织中IL-18表达水平及室性心律失常诱发率均高于假手术组(P< 0.01).麝香保心丸低剂量组第2周末时梗死边缘带心肌组织中IL-18表达水平及室性心律失常诱发率显著低于模型组(P< 0.05),而第1周末时则无显著差异.麝香保心丸高剂量组第1、2周末梗死边缘带心肌组织中IL-18表达水平及室性心律失常诱发率显著低于模型组(P< 0.01).麝香保心丸高剂量组梗死边缘带心肌组织中IL-18表达水平及室性心律失常诱发率在第1周末(P< 0.01)、第2周末(P< 0.05)时均显著低于低剂量组.结论 麝香保心丸可通过抑制IL-18过度表达而降低急性心肌梗死后室性心律失常诱发率,其作用呈剂量相关性.

Effect of Shexiang Baoxin Pill on time difference expression of IL-18 in border zone myocardium and ventricular arrhythmia of rats with acute myocardial infarction

Objective To investigate the effect of Shexiang Baoxin Pill (SBP) on the inhibition of ventricular arrhythmia of rats with acute myocardial infarction. Methods Ninety male model rats induced by left anterior descending branch ligation were randomly divided into model group, high-dose SBP treatment group, and low-dose SBP treatment group (45.0 and 22.5 mg/kg) equally (n = 30). Every group was further divided into the 1st weekend and the 2nd weekend subunits equally (n = 15). Twenty rats were taken as the Sham operation group which was further divided into the 1st weekend and the 2nd weekend subunits equally (n = 10). The rats in the high- and low-dose groups were respectively treated by ig administration of SBP for 1 or 2 weeks from day 2 after the administration, whereas the rats in the Sham operation group were not given any treatment. At the 1st weekend and the 2nd weekend, programmed electrical stimulus was imposed on the rat hearts to induce the ventricular arrhythmia. Then the left ventricle free wall tissue in the Sham operation group and the border zone myocardium in the rest of rats were preserved. The expression of myocardial IL-18 was determined. Results Compared to the the Sham operation group, there were higher expression of myocardial IL-18 and the induced ratio of ventricular arrhythmia at 1st weekend and 2nd weekend in the model group (P <0.01). Compared to the model group, low-dose SBP treatment could reduce the expression of myocardial IL-18 and the induced ratio of ventricular arrhythmia at 2nd weekend (P <0.05), but there was no difference on the expression of myocardial IL-18 and the induced ratio of ventricular arrhythmia at the 1st weekend. Compared to the the model group, high-dose SBP treatment could reduce the expression of myocardial IL-18 and the induced ratio of ventricular arrhythmia at the 1st weekend and the 2nd weekend (P <0.01). Compared to the low-dose SBP group, high-dose Shexiang Baoxin Pill treatment could reduce the expression of myocardial IL-18 and the induced ratio of ventricular arrhythmia at the 1st weekend (P <0.01) and the 2nd weekend (P <0.05). Conclusion SBP may reduce the induced rate of ventricular arrhythmia of rats after acute myocardial infarction by inhibiting the over-expression of myocardial IL-18, which is in a dose dependent manner.