【作者】 孙娜；

【导师】 金学隆； 郝洪谦；

【作者基本信息】 天津医科大学 ， 生理学， 2008， 硕士

【摘要】 目的:1.建立大鼠迷走神经背核电刺激模型。2.分析电刺激迷走神经背核条件下大鼠空肠电活动的变化。3.观察电刺激迷走神经背核条件下的大鼠空肠微循环的变化。4.探讨迷走神经背核兴奋引起的大鼠小肠生理机能的改变,从电生理和微循环方面对迷走神经背核在急性脑血管病引起的应激性溃疡中的作用提供重要的参考依据。方法:1.建立大鼠迷走神经背核电刺激模型:麻醉大鼠,固定于鼠脑立体定位仪上。根据大鼠脑立体定位图谱,利用立体定位仪准确定位迷走神经背核,于定位点利用牙科钻施行颅骨打孔术,用牙科粉固定刺激电极,建立迷走神经背核电刺激的大鼠模型。2.大鼠空肠电活动计测:大鼠禁食12-18小时,常规麻醉,沿腹部正中打开腹腔,暴露空肠,将双针状电极插于浆膜下,两电极间距离大约为2mm,接通RM6240B型多道生理信号采集处理系统记录大鼠迷走神经背核电刺激前与刺激后的大鼠消化间期空肠电活动。3.大鼠空肠微循环变化的计测:大鼠禁食12-18小时,常规麻醉,沿腹部正中打开腹腔,暴露空肠在10倍镜下按微血管分级原则选取直径10-30μm的微静脉,使用BI-2000微循环动态图像分析系统测量微静脉的血流速度并予以记录。4.大鼠迷走神经背核电刺激后脑组织大体标本及核团电毁损标本的制备:大鼠迷走神经背核电刺激造模,实验结束后,在相应核团上通以阳极电压5.0 V,60 Hz,20-30 s。断头取脑,置入福尔马林溶液。2-3 d后,冷却切片检查定位是否准确。5.统计学方法:采用SPSS13.0统计分析软件进行数据分析。大鼠迷走神经背核电刺激前后的空肠慢波变化及微循环血流速度的变化采用配对t检验分析;电刺激前和刺激1分钟内快波出现概率采用采用χ~2检验的Fisher’s确切概率法进行分析,快波出现率的变化采用χ~2检验的方法进行分析。结果:1.通过大体标本、电毁损针道确定刺激部位正位于迷走神经背核。2.比较大鼠迷走神经背核电兴奋引起的空肠电活动的变化。迷走神经背核电刺激后10分钟大鼠空肠慢波平均频率增加(P＜0.05),平均振幅增加(P＜0.05)。迷走神经背核电刺激1分钟内和刺激前1分钟相比,平均频率降低(P＜0.01),平均振幅增加(P＜0.01),快波发生概率增加(P＜0.05),快波出现率增加(P＜0.01)。3.比较大鼠迷走神经背核电刺激前后空肠系膜微循环血流速度的变化,可见电刺激迷走神经背核后空肠系膜微血管血流速度加快(P＜0.01)。结论:1.利用脑立体定位技术可准确制作迷走神经背核电刺激的动物模型。2.迷走神经背核电刺激后大鼠空肠电活动表现异常,主要表现为刺激即时动作电位高发,肠收缩运动增强;刺激后和刺激前相比慢波频率、振幅均增加。该结果提示,中枢神经系统损伤可能通过兴奋迷走神经背核进而对消化道平滑肌的功能活动产生影响,这种机制有可能通过支配消化道的神经电活动完成,最终会影响消化道的运动,成为应激性溃疡的神经电生理基础。3.迷走神经背核电刺激后空肠系膜微循环血流速度加快。该结果提示,中枢神经系统损伤可能通过兴奋迷走神经背核,造成消化道粘膜微循环的紊乱。更多还原

【Abstract】 The study on the dependablity between the electric stimulus of the dorsal motor nucleus of the vagus and myoelectric activity in the small intestine of RatsObjective:1.To establish the model of electric stimulus of the dorsal motor nucleus of the vagus of rats.2.Investigate the changes of small intestine myoelectric activity after electric stimulus of the dorsal motor nucleus of the vagus.3.Investigate the changes of the microcirculation in the small intestine after electric stimulus of the dorsal motor nucleus of the vagus.4.To explore the changes of the gastrointestinal function after the excitation of the dorsal motor nucleus of the vagus,and make an important reference for effect of the dorsal motor nucleus of the vagus in the stress ulcer induced by acute cerebrovascular disease.Methods:1.Preparation of electric stimulus of the DMV animal model:Anesthetized rats,fix it on the rats stereotaxis instrument.According to the rats brain stereotaxic atlas, located the DMV through stereotaxis instrument.An operation was made to open the skull by auger.Fix the stimulating electrode with gutta pertscha,and made the electric stimulus of the DMV animal model animal model.2.Measurement of myoelectric activity in small intestine:Absoluted diet for 12-18 hours,rout anesthesia,gave laparotomy on median ventral,exposed jejunal,put electrode with two needles into ectoptygma,and the distance between two needles was about 2mm.Connected with RM-6240B biological signal collecting and processing system,and measured jejunal myoelectric activity during digestion period of both before and after the electric stimulus of the DMV. 3.Measurement of small intesine microcirculation:Absoluted diet for 12-18 hours, rout anesthesia,gave laparotomy on median ventral,exposed jejunal,choose the veinule with diameter of 10-30μm according to the blood capillary grading under the microscope in 10 times.Record the blood flow rate of the veinule with the BI-2000 microcirculation dynamic image analysis system.4.Preparation of rat’s brain tissue and lesion of the DMV after electric sitimulus: establish the animal model of electric sitimulus of DMV,after the experiment,an additional stimulation for 20-30s was conducted to create a lesion around the tip of the electrode for later histologic verification.,the stimulation parameters were 5.0V and 60 Hz.At the end of the stimulation procedures,each brain was soaked in a 10%formalin phosphate buffer.2-3 days later,to confirm the location of the DMV.5.Statistical analysis:Statistical software SPSS 13.0 was used.The differences of changes of the slow wave and blood flow rate were compared by paired t test,the difference of the occurrence of the spike potentials before and immediately of the sitmulus of the DMV was compared by x~2 test.Results:1.We confirm that the place stimulated were in the DMV through the preparation of rat’s brain tissue and the lesion around the tip of the electrode.2.Compared jejunum myoelectric activity induced by electric stimulus of the DMV. The frequency of the slow waves in the myoelectric activity of the jejunum increased(P＜0.05);the amplitude of the slow waves in the myoelectric activity of the jejunum incresased(P＜0.05);the occurrence of the action potential before and immediately of the sitmulus of the DMV increased(P＜0.01).Conclusions:1.We can establish the accurate animal model of electric stimulus of the dorsal motor nucleus of the vagus of rats by means of stereotactic method successfully.2.Intestine myoelectric activity after electric stimulus of the DMV is abnormal,the appearance is mainly the frequency of the action potentials significant increased, the frequency and amplitud of the slow wave increased after the stimulation,That means the gastrointestinal fuction abnormal induced by the damage of the central nerve system mabe conducted by the gastrointestinal myoelectric activity.It come to be the neural electrophysiologic basis of the stress ulcer.3.The blood flow rate of the veinule in the jejunum mesenterium increased after stimulation.That means the the damage of the central nerve system mabe conducted by exciting the DMV,and finally make effect on the disorder of the gastrointestinal microcirculation.更多还原