Analysis of the Change of Intestinal Myoelectricity in Rats with Stimulation of the Dorsal Motor Nucleus of the Vagus
|School||Tianjin Medical University|
|Keywords||The vagus nerve nucleus Electrical excitability Myoelectric complex of the small intestine to digest interval Spike Microcirculation|
Objective: In this study, using rat nerve nuclei positioning technology and electrical stimulation means vagus nerve dorsal nucleus (Dorsal Motor Nucleus of the Vagus DMV) to observe the dynamic changes of the small intestine to digest DMV electrical excitability under conditions composite EMG activity, as well as empty mesenteric microcirculation blood flow changes, from a physiological point of view of electrical nerve DMV electrical excitability of gastrointestinal myoelectric activity. Method: 1. Experimental animals: healthy wistar rats, male, clean grade, weighing 254 ± 6g, provided by the Experimental Animal Center of Peking Union Medical College, China Institute of Radiation Medicine. Rat fans go Dorsal nuclear localization and electrode fixed: anesthetized rats, fixed in the rat brain stereotaxic apparatus, according to the rat stereotaxic coordinates accurate positioning right vagus nerve dorsal nucleus of the dental drill point at the skull surface positioning purposes skull playing hole surgery, according to the positioning depth stimulating electrodes vertically into the fans will take the dorsal motor nucleus of self-curing dental powder fixed electrode. Electrical stimulation parameters: pulse width 0.3ms, strength 0.2mA, frequency 50Hz, stimulus duration 40s. Vagus nerve back nuclear damage and rats after general anesthesia, using the above method of positioning stimulating electrodes given direct current stimulation: 1mA, 100Hz, 10s electrolytic lesion, after the damage to the brains were removed, fixed in 10% formalin solution specimens provisioning: along the needle points largely sliced, with reference to the atlas to determine the location of the stimulation points. 4 electrical stimulation of the vagus nerve dorsal nucleus of rat jejunum before and after the measurement of EMG activity: rats were fasted for 12 hours, general anesthesia and abdominal cavity was opened along the middle of the abdomen, exposed jejunum, double-needle electrode inserted in the subserosal two electrode The distance between about 2mm, turned BL-410 the biodynamics experiment system records of jejunum electromyographic activity in the rat interdigestive stable after 20 minutes, giving the 40 minutes of stimulation before and after each recording, using an image analysis system to collect data. Analysis before and after stimulation rat jejunum EMG activity duration, activity period average per minute fast wave, cycle time and activity / cycle ratio. 5. Electric stimulation fans to go before and after the nerve back nuclear rat jejunum mesenteric micro cycle count measurement: rats were fasted for 12 hours after general anesthesia, the use of the above methods conducted fans go dorsal approved bit and electrode fixed, along the middle of the abdomen open the abdominal cavity free upper jejunum intestine. The rat lateral position, bowel and pipe loop placed on the stage, under conditions of constant temperature water bath, the microcirculation of BI-2000 camera system continuously measuring the electrical stimulation of the vagus nerve back empty before and after the nuclear mesenteric microcirculation blood flow velocity changes . 6 Statistical Methods SPSS11.5 statistical software for data analysis. Electrical stimulation of the fans to take the nerve dorsal nucleus before and after the interdigestive migrating myoelectric complex cycle when the process with active / cycle ratio, active phase average per minute faster wave number, as well as the total activity period duration, mesenteric microcirculation blood flow speed are using self-control, paired t-test, given the significant level α = 0.05. The results: 1. Vagus nerves back under the conditions of nuclear excited jejunal myoelectric activity of the total duration increased (P lt; 0.01) jejunal myoelectric activity period average per minute faster increase in the wave number (P lt; 0.01). Vagus nerve back under the conditions of nuclear excited intestinal interdigestive myoelectric complex (IMC) cycle time shortened (P lt; 0.01) interdigestive myoelectric complex activities / cycle ratio increased (P lt; 0.05). 3.DMV electrical stimulation under the conditions of the jejunal mesentery microcirculation blood flow velocity than the control group increased (P lt; 0.05). Conclusion: to electrical stimulation excited DMV myoelectric activity of rat small intestine behave abnormally, specific performance for the duration of the active phase and per minute faster increase of the wave number, suggesting that electrical stimulation of DMV lead myoelectric activity of the small intestine enhancement. The rats 2.DMV electrical excitability IMC cycle shortened the activity cycle ratio increases, suggesting that electrical stimulation of the DMV under the conditions, intestinal emptying speed up this speed up in IMC resting shortened based. 3.DMV electrical excitability rat small intestine mesentery microcirculation blood flow velocity accelerated prompt DMV electrical excitability mesenteric microcirculation hemodynamic changes.