交感神经和肌间神经丛在胃电刺激调控胃慢波中的作用

Effect of sympathetic nerve and myenteric nerve plexus on gastric slow waveafter electrical stimulation

目的研究胃交感神经及肌间神经丛在电刺激调控胃慢波活动中的作用,确定胃电起博的神经机制和作用环节,为今后起搏器的深入研究打下基础。方法10只雄性wistar大鼠随机分为对照组和电刺激组,各5只。全部大鼠植入浆膜电极,电刺激组大鼠行胃电刺激至胃慢波被完全控制。植入电极组不行电刺激。采用免疫组化S P法检测并比较两组大鼠胃窦肌间神经丛和脊髓后角C fos蛋白表达。结果电刺激组大鼠胃慢波全部被完全控制,所需能量为2 70±80 .6ms ,2mA。2组大鼠脊髓中间内侧核,中间外侧核均未见C fos阳性神经元,而后角浅层均见散在C fos表达,比较无显著性差异(P >0 .0 5 )。植入电极组胃窦肌间神经丛未见C fos阳性神经元,电刺激组胃窦肌间神经丛可见C fos阳性神经元。结论适宜参数的胃电刺激可完全控制大鼠胃慢波。肌间神经丛参与胃电刺激调控胃慢波,而交感神经则无明显作用。

Objective To investigate the nervous mechanism of gastric electrical simulation in regulating the gastric slow wave and demonstrate the roles of sympathetic nerve and myenteric nerve plexus in the entrainment.Methods Ten male Wistar rats were randomly divided into two sessions.All rats were implanted with two pairs of electrodes on gastric serosa.In one session, long-pulse electrical stimulation was applied until completed entrainment was controled.In the other session,no stimulation was applied.Imunohistochemistry was used to detect c-fos expression in myenteric plexus of the whole layer preparation of gastric antrum and in posterior horn of spinal cord,and the difference of c-fos-positive neuron number between the two sessions was also identified.Results Completed entrainment was achieved in all of the five rats, the effective pulse width was from 200 ms to 300 ms,with the pulse amplitude of 2 mA.There was no c-fos-immunoreactive neuron in intennedionedial nucleus and intermediolateral nucleus of two sessions. Some dispersing c-fos expression in superficial lamina of posterior horn was detected, and there was no difference between two sessions(P>0.05). There were average ~6.40 ±2.79 (n=5) c-fos immunoreactive neurons in myenteric plexus of stimulated rats, but there was no one in rats without stimulation.Conclusions Electrical stimulation with proper parameter can completely entrain gastric slow wave of rats. Myenteric plexus may play a role in this entrainment,but sympathetic nerve may not.