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目的:观察预先电刺激小脑顶核对心肌梗死大鼠心脏去甲肾上腺素水平和乙酰胆碱释放的影响。方法:实验于2003-07/11在重庆医科大学附属第一医院心血管疾病研究所完成。取健康Wistar大鼠98只,随机分为4组:①心肌梗死组(n=30):结扎左冠状动脉前降支。②电刺激组(n=30):预先电刺激小脑顶核1h再予以左冠状动脉结扎。③小脑顶核毁损组(n=30):毁损小脑顶核5d后电刺激小脑顶核1h,再行左冠状动脉结扎。以上3组又分别分为心肌梗死后1,7,21d3个时相组,每组10只。④假手术组(n=8):开胸术后仅在左冠状动脉前降支下穿线但不结扎,电极插入小脑顶核,但不与予以刺激。各组分别于相应时间点处死大鼠后,取心肌梗死区和非梗死区组织标本,测定心脏去甲肾上腺素含量应用高效液相色谱法;检测心脏乙酰胆碱酯酶活性应用生化方法,表示乙酰胆碱释放量。结果:去除死亡、心肌未梗死、小脑顶核电刺激或毁损失败的大鼠,最终54只大鼠进入结果分析,心肌梗死组、电刺激组、小脑顶核毁损组、假手术组分别为13,20,13和8只。①各组大鼠心肌梗死病程中左室非梗死区及梗死区心肌去甲肾上腺素含量的比较:心肌梗死第1天,心肌梗死组及小脑顶核毁损组大鼠心肌组织中去甲肾上腺素水平均较假手术组升高(q=12.080～15.396,P<0.01),电刺激组大鼠心肌去甲肾上腺素含量显著低于心肌梗死组(q=9.934,10.821,P<0.01)。心肌梗死第21天,小脑顶核毁损组大鼠非梗死区心肌去甲肾上腺素含量显著低于假手术组及心肌梗死组(q=5.283,3.780,P<0.05～0.01)。②各组大鼠心肌梗死病程中左室非梗死区及梗死区心肌乙酰胆碱酯酶活性的比较:心肌梗死第1天,心肌梗死组及小脑顶核毁损组大鼠心肌组织中乙酰胆碱酯酶活性均显著低于假手术组(q=4.339～5.318,P<0.01),电刺激组大鼠心肌乙酰胆碱酯酶活性显著高于心肌梗死组(q=5.449,4.465,P<0.01)。心肌梗死第21天,小脑顶核毁损组大鼠非梗死区心肌的乙酰胆碱酯酶活性显著低于假手术组(q=3.843,P<0.05)。结论:电刺激小脑顶核可降低心肌梗死大鼠早期心脏梗死区或非梗死区去甲肾上腺素水平,增加乙酰胆碱释放。
Objective: To observe the effect of preconditioning of cerebellar fastigial nucleus on the cardiac norepinephrine level and the release of acetylcholine in myocardial infarction rats. Methods: The experiment was performed at the Institute of Cardiovascular Diseases, the First Affiliated Hospital of Chongqing Medical University from July to July 2003. 98 healthy Wistar rats were randomly divided into 4 groups: ① myocardial infarction group (n = 30): ligation of left anterior descending coronary artery. ② electrical stimulation group (n = 30): pre-electrical stimulation of the cerebellum for 1h and then left coronary artery ligation. ③ cerebellar caudate nucleus damage group (n = 30): 5 days after injury, the cerebellar fastigial nucleus electrical stimulation of the cerebellar apical nucleus 1h, then the left coronary artery ligation. The above three groups were also divided into three groups: 1, 7, 21 d after myocardial infarction, 10 in each group. ④ Sham operation group (n = 8): Thoracotomy was performed only in the anterior descending branch of the left coronary artery but not ligated. The electrode was inserted into the apical cerebellum, but it was not stimulated. The rats in each group were killed at the corresponding time points after myocardial infarction area and non-infarcted tissue samples were taken, the determination of cardiac norepinephrine content using high performance liquid chromatography; detection of cardiac acetylcholinesterase activity using biochemical methods that the release of acetylcholine the amount. Results: The final 54 rats were killed, the myocardial infarction was not induced, and the fastigial nucleus electrical stimulation or failure was failed. The final result was analyzed. The myocardial infarction group, electrical stimulation group, cerebellar fastigial nucleus damage group and sham operation group were 13, 20, 13 and 8 only. ①Comparison of left ventricular non-infarct area and myocardial norepinephrine content in myocardial infarction area in each group during the course of myocardial infarction: On the first day after myocardial infarction, myocardial tissue of myocardial infarction group and caudate nucleus cerebellar caudal nornicotine (Q = 12.080 ~ 15.396, P <0.01). The content of norepinephrine in myocardium of rats in electrical stimulation group was significantly lower than that in myocardial infarction group (q = 9.934,10.821, P <0.01). On day 21 of myocardial infarction, the content of norepinephrine in non-infarct zone of cerebellar fastigial nucleus lesion group was significantly lower than that in sham operation group and myocardial infarction group (q = 5.283, 3.780, P <0.05-0.01). ② Comparison of myocardial AChE activity in left ventricular non-infarct area and infarct area in myocardial infarction course in each group: AChE activity in myocardium of myocardial infarction group and caudate nucleus lesion group was (Q = 4.339-5.318, P <0.01). The AChE activity of myocardium in electrical stimulation group was significantly higher than that in myocardial infarction group (q = 5.449, 4.655, P <0.01). On the 21st day after myocardial infarction, the AChE activity in myocardium of non-infarct zone in cerebellar fastigial nucleus lesion group was significantly lower than that in sham operation group (q = 3.843, P <0.05). Conclusion: Electrical stimulation of the cerebellar fastigial nucleus can reduce the levels of norepinephrine and increase the release of acetylcholine in early infarction or non-infarcted area of myocardial infarction rats.