小脑顶核刺激对急性心肌梗死大鼠心率变异性的影响

Influence of Fastigial Nucleus Stimulation on Heart Rate Variability of Surgically Induced Myocardial Infarction Rats

目的观察电刺激小脑顶核(FNS)对急性心肌梗死(AMI)大鼠心率变异性(HRV)的影响。方法成年雄性SD大鼠100只随机分为:AMI组(n=30),单纯结扎左冠状动脉(LCA);小脑顶核刺激(FNS)组(n=30),结扎LCA,1h后电刺激左侧小脑顶核1h;小脑顶核损毁(FNL)组(n=30),先用鹅膏氨酸毁损两侧小脑顶核,5d后再按FNS组方法操作;假手术组(n=10),开胸手术后仅在LCA下穿线但不结扎,电极插入小脑顶核,但不予刺激。各组又分开胸术后6h、1d、7d、21d4个时间点,分别采用大鼠HRV记录分析系统进行HRV频域分析。结果结扎6h,FNS组频域分析指标—低频成分明显低于AMI和FNL组(P<0.01),高频成分明显高于其他干预组(P<0.01);结扎1d后,FNS组仍然呈现高频成分的增加和低频成分的下降(P<0.05);7d后,只有假手术组保留了较高的高频功率,各干预组之间的差别消失;21d后,各组HRV参数之间无差别。FNL组与AMI组比较,各时间段HRV参数比较无显著性差异(P>0.05)。结论电刺激小脑顶核可改善AMI大鼠的HRV。

Objective To observe the effect of fastigial nucleus stimulation （FNS） on heart rate variability （HRV） of surgically induced myocardial infarction rats. Methods 100 Sprague-Dawley rats were randomly allocated in four groups, including sham-operation control group, rats with coronary arteries ligated but fastigial nucleus （FN） sham stimulated （AMI group）, rats both coronary arteries ligated and FN stimulated （FNS group）, and rats on which FN lesioned 5 d before, then coronary arteries ligated and FN stimulated （FNL group）. HRV characteristics were determined 6 h, 1 d, 7 d and 21 d after the ligation, and mortality rates were observed after 21 d. Results FNS can improve the survival of myocardial infarction rats, and this may be due to the increased vagal tone and decreased sympathetic tone. Conclusion FNS may have cardio-protective effects on surgically induced myocardial infarction rats.