豚鼠肠系膜下神经节及其结肠段离体标本的反射活动

Reflex Activities in An in Vitro Preparation of Inferior Mesenteric Ganglia and Distal Colon of the Guinea-Pig

选用豚鼠肠系膜下神经节(IMG)及其支配的远端结肠联合标本,观察神经节内突触传递与结肠纵、环肌活动的相互关系。结果表明:纵、环肌预置张力为零时,节细胞内可记录到自发的快速电位波动,切断结肠神经,电位立即不可逆地消失。径向扩张结肠,在IMG细胞还可记录到一种与迟慢兴奋性突触后电位相似的持续70～190s的去极化电位波动,该电位具有抗箭毒和阿托品性质,而这种缓慢去极化电位能与刺激神经诱发的迟慢兴奋性突触后电位发生总和。串刺激IMG节前神经,纵肌舒张,而环肌运动不规则。以上结果提示:在肠-神经-肠反射通路中存在着胆碱能和非胆碱能性突触活动,两者协调地控制着肠道的运动。

By using the preparation of inferior mesenteric ganglia (IMG) associated with distal colon of guinea-pig, the relationship between synaptic transmission in ganglion cell and movement of longitudinal and circular muscles of colon was investigated. It was found that when the preload tention of both muscles was set 0, the spontaneous synaptic potentials were recorded in IMG cells. Cutting colonic nerve irreversibly eliminated the potentials. Radialy distending the colon induced a slow depolarization lasting for about 70-190s in IMG neurones, This slow potential was resistant to d-TC and atropine. In addition, the summation of the slow potential induced by distending colon and ls-EPSP evoked by stimulating hypogastric nerve could, be observed. A train stimulation of pre-ganglionic nerve caused the relaxation of the longitudinal muscle, but irregulation in the motion of the circular muscle. The results suggest that cholinergic and non-cholinergic activities were included in the colon-IMG-colon reflex in which they control the movements of the intestines coofdinately.