【摘要】 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。更多还原

【Abstract】 AIM: To study the effects of cerebellar fastigial nucleus electro-stimulation in advance on the cardiac norepinephrine concentrations and acetylcholine release after myocardial infarction in rat hearts. METHODS: The experiment was conducted in the Institute of Cardiovascular Disease, First Affiliated Hospital of Chongqing Medical University from July to November 2003. Ninety-eight healthy Wistar rats were randomly divided into 4 groups: ① The rats in myocardial infarction group (n=30) were ligated the anterior descending branch of the left coronary artery. ② The rats in the electro-stimulation group (n=30) were treated with electro-stimulation at cerebellar fastigial nucleus for 1 hour before producing ligation on left coronary artery. ③ The rats in the cerebellar fastigial nucleus lesion group (n=30) were treated with electro-stimulation at cerebellar fastigial nucleus for 1 hour after impairing the cerebellar fastigial nucleus for 5 days, and then performing deligation on left coronary artery. The above 3 groups were assigned into 1, 7 and 21 days post-myocardial infarction subgroups, respectively with 10 in each group. ④ The rats in the sham operation group (n=8) were worn thread through anterior descending branch of left coronary artery only after tnoracotomy without deligation. Electrode was inserted into cerebellar fastigial nucleus without stimulation. The rats were sacrificed at matched time point, the tissue samples in myocardial infracted and non-infarcted regions were taken. Content of cardiac norepinephrine was measured with high performance liquid chromatography, and the activity of acetylcholinesterase, which was used to express the levels of acetylcholine, was measured with biochemistry method. RESULTS: The rats, which failed to live, to produce myocardial infarction, to stimulate or to destroy fastigial nucleus correctly, were rejected. At the end of the study, the complete data were obtained in 54 rats with 13 in myocardial infarction group, 20 in electro-stimulation group, 13 in fastigial nucleus lesion group, and 8 in sham operation group. ① Comparison of content of myocardial norepinephrine in infracted and non-infarcted regions of left ventricle in progress of myocardial infarction in every group: At the first day of myocardial infarction, levels of cardiac norepinephrine in myocardial tissues in myocardial infarction group and cerebellar fastigial nucleus lesion group were greatly higher than those in sham operation group (q=12.080-15.396, P < 0.01). The content of cardiac norepinephrine of rats in the electro-stimulation group was lower significantly than that in the myocardial infarction group (q=9.934,10.821, P < 0.01). At the 21st day of myocardial infarction, the content of cardiac norepinephrine of rats in the non-infarcted region of rats in the cerebellar fastigial nucleus lesion group was lower obviously than that in the sham operation group and the myocardial infarction group (q=5.283,3.780, P < 0.05-0.01). ② Comparison of activity of myocardial acetylcholinesterase at non-infarcted and infarcted of the left ventricle in the progress of myocardial infarction of rats in every group: At the first day of myocardial infarction, the activity of acetylcholinesterase in myocardial tissue of rats in the myocardial infarction group and cerebellar fastigial nucleus lesion group was markedly lower than that in the sham operation group (q=4.339-5.318, P < 0.01). The activity of myocardial acetylcholinesterase of rats in the electro-stimulation group was remarkably higher than that in the myocardial infarction group (q=5.449,4.465, P < 0.01). At the 21st day of myocardial infarction, the activity of acetylcholinesterase in the non-infarcted region of rats in the cerebellar fastigial nucleus lesion group was lower significantly than that in the sham operation group (q=3.843,P < 0.05). CONCLUSION: The cerebellar fastigial nucleus electro-stimulation can decrease the level of norepinephrine in the infracted or non-infarcted region and increase the release of acetylcholine in rats at an early stage after myocardial infarction.更多还原