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 Rats

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.