电针对大鼠三叉神经尾侧脊束核内P物质影响的免疫及超微免疫细胞化学研究

用免疫细胞化学及免疫电镜方法研究了电针对大鼠三叉神经尾侧脊束核内ＳＰ的影响以及含ＳＰ的轴突终末的突触联系。结果表明,电针大鼠“人中”、“承浆”穴后痛阈明显提高（Ｐ＜０．０１）,三叉神经尾侧脊束核内ＳＰ免疫反应活性也较对照组明显增加（Ｐ＜０．０１）。三叉神经尾侧脊束核内含ＳＰ轴突终末内含有密集的清亮透明小泡、少量大颗粒小泡及线粒体,轴突终末内的ＳＰ免疫反应产物分布于大颗粒小泡内和清亮小泡壁上。含ＳＰ的轴突终末主要与三叉神经尾侧脊束核内神经元的树突形成轴－树突触;极少数ＳＰ阴性轴突终末与ＳＰ阳性轴突形成轴－轴突触或接触。电针可能通过轴－轴突触的突触前抑制方式,抑制了三叉神经初级传入细纤维ＳＰ的释放,从而参与针刺镇痛过程。

THE IMMUNOCYTOCHEMICAL AND ULTRAIMMUNOCYTOCHEMICAL OBSERVATION ON THE INFLUENCE OF ELECTRO-ACUPUNCTURE UPON SUBSTANCE P IN THE CAUDAL SPINAL TRIGEMINAL NUCLEUS OF THE RAT

To determine the changes of substance P (SP) during electroacupuncture at points "Renzhong" and "Chengjiang", and the synaptic connections of the substance P-containing axon terminals in caudal spinal trigeminal nucleus of rat, the present study was made using immuncoytochemical (SPA) and electro-microscopic methods.Twenty healthy adult rats were divided into experiment and control groups. After electro-acupuncture at points"Renzhong" and "Chengjiang", and following perfusion, the brains of experiment and control rats were removed. The immunocytochemical (SPA) procedure of sections were made with SP antibody. sections containing SP stained elements were subjected to light microscopy and a part of the sections were prepared for electron microscopy.The experiment results are as follows:1. The pain threshold of animal in the experiment group was obvious raised after electro-acupuncturing at points "Renzhong"and"Chengjiang"(P<0.01).2. The immunoreactivity of substance P-containing axon terminal was obviously increased in the experiment group than the control group. The SP-like immunoreactive product were mainly distributed in large dense cored vesicles and on the membrane of the surface of small clear vesicles.3. The substance P-containing axon terminal contacts with an unlabelled dendrite to form the axo-dendritic synapses. Occasionally, the negative axon terminal contacts or synapses with substance P-containing axon terminal to constitute the axo-axonic synapse.The present results provide the ultraimmunocytochemical basis for the mechanism of the facial acupuncture analgesia.