针刺“足三里”对大鼠孤束核P物质的影响

Effect of Electroacupuncture of "Zusanli" Point on Substance P in the Nucleus of the Solitary Tract

目的 :观察延髓孤束核P物质免疫阳性反应产物的分布以及针刺“足三里”穴对其的影响。方法 :将SD大鼠随机分为三组 :电针“足三里”穴组 (n =10 )、电针“足三里”穴旁开 0 5cm组(n =10 )、空白对照组 (n =10 )。应用免疫组织化学ABC法显示延脑组织SP免疫活性切片。结果 :孤束核内P物质的免疫阳性反应产物以膨体型纤维为主 ,呈点状和串珠状 ,其敞开部有少量阳性胞体。主要分布于孤束核的内侧亚核、连合亚核 ,其余亚核内较为稀疏 ;电针“足三里”穴内侧亚核、连合亚核阳性纤维的光密度明显升高 ,其余亚核无明显变化 ;电针“足三里”穴外侧旁开 0 .5cm组与空白组相似 ,各亚核均无明显变化。结论 :针刺“足三里”可能通过抑制NTS内侧亚核和连合亚核SP的释放 。

Objective: To observe the distribution of substance P like immunoreactivity(SP LI) in the nucleus of solitary tract(NTS)and the effect of electroacupuncture(EA) at 'Zusanli' (ST 36) on SP. Methods: Thirty SD rats were randomly and evenly divided into control group, 'Zusnali' group and Non acupoint (about 0.5 cm beside 'Zusali') group. EA (sparse dense waves, frequency of 16～ 20 Hz and strength that is able to induce slight muscular tremor) was applied to bilateral 'Zusanli' (ST 36) for 20 min.Avidin biotin peroxidase complex (ABC) method of immunohistochemistry was employed to display SP LI of the bulb tissue sections. Results: Under light microscope,SP immuno reaction products mainly were cirsoid fibers,presenting dot like or strings of bead like, distributing mainly in the medial and commissural subnucleus of NTS (mNTS, cNTS) and the spinal nucleus of trigiminal nerve; while no immunoreactive neurons were seen in NTS. After EA stimulation of 'Zusanli ' (ST 36) , the light density of SP LI in the mNTS and cNTS increased significantly in comparison with control group and non acupoint group (P<0.05～0.01). No significant changes were seen in other nuclei as dorsal motor nucleus of the vagus, area postrema, etc. There was also no obvious difference between non acupoint group and control group in SP LI changes in every subnucleus of NTS. It showed that EA of 'Zusanli'(ST 36) could inhibit release of SP. Conclusion: NTS is an important primary centre responsible for the regulative action of EA of 'Zusanli' (ST 36) on the physiological activities of the stomach.