小脑顶核电刺激对心肌梗死大鼠死亡率及动脉压力感受性反射敏感性的影响

Effects of fastigial nucleus electro-stimulation on mortality and arterial baroreflex sensitivity in rats after myocardial infarction

目的观察小脑顶核电刺激(FNS)对心肌梗死(MI)大鼠死亡率及动脉压力感受性反射敏感性(BRS)的影响。方法 90只SD大鼠随机分为3组,每组30只:①MI组,仅结扎左冠状动脉前降支(LAD);②FNS组,预先FNS1h再予以LAD结扎;③小脑顶核毁损组,毁损小脑顶核5d后FNS1h,再行LAD结扎;各组又分MI后1、28d两个亚组。另设假手术组(n=8)。LAD结扎1、28d后,连续监测存活大鼠血压,测定BRS,并计算28d累积死亡率。结果①FNS组总死亡率明显低于MI组或小脑顶核毁损组(P<0.05)。②LAD结扎1d、28d后,与假手术组比较,MI组或小脑顶核毁损组大鼠BRS均明显降低(P<0.01);与MI组比较,FNS组大鼠BRS明显增加(P<0.01);小脑顶核毁损组与MI组BRS比较差异无统计学意义(P>0.05)。结论①FNS减少MI大鼠死亡率。②FNS可恢复MI大鼠受损的动脉压力感受性反射功能。③FNS减少MI后大鼠死亡率可能与其改善BRS有关。

Objective To investigate the effects of fastigial nucleus electro-stimulation（ FNS） on the mortality and arterial baroreflex sensitivity（ BRS） in rats after myocardial infarction（ MI） . Methods Ninety-eight SD rats were selected,and 90 of them were randomly divided into 3 groups with 30 rats in each group： MI group,FNS group and fastigial nucleus lesion group. In MI group,left anterior descending artery of rats was ligated. In FNS group,rats were pretreated with fastigial nucleus electro-stimulation for 1 h,and then left anterior descending artery was ligated. In fastigial nucleus lesion group,rats were treated with fastigial nucleus electro-stimulation for 1 h after fastigial nucleus was damaged for 5 d,and then left anterior descending artery was ligated. Each group was subdivided into 2 subgroups according to the two time points of 1,28 days after ligation of left anterior descending artery. The other 8 rats were taken as sham-operated group. At 1,28 day after ligation of left anterior descending artery,blood pressure was continuously recorded in those survival rats; and BRS was measured at same time,as well as the 28 d cumulative mortality was recorded. Results ①Total mortality in FNS group was significantly lower than that in MI group or fastigial nucleus lesion group（ P 0. 05） . ②BRS in MI group or fastigial nucleus lesion group was significantly lower than that in sham-operated group（ P 0. 01） ; but BRS in FNS group was significantly higher than in MI group（ P 0. 01） . There was no significant difference in BRS between MI group and fastigial nucleus lesion group（ P 0. 05） . Conclusion ①FNS can reduce the mortality of rats after myocardial infarction. ②FNS can help MI rats rehabilitate from impairment of arterial baroreflex function. ③The reduction of mortality coming from FNS in rats after myocardial infarction may be related to FNS improving BRS.