P物质阳性表达神经纤维在大鼠心包经五输穴局部皮肤组织中的分布

Distribution of Substance P-positive Nerve Fibers in Local Skin Tissues of Five Shu-points of the Pericardium Meridian in the Rat

目的:通过观察P物质(SP)阳性表达神经纤维在心包经五输穴中井、荥、输、经、合每个腧穴局部皮肤中的显微结构特征,揭示不同腧穴之间神经支配的差异。方法:将6只正常大鼠用4%多聚甲醛经过心脏灌流后取下"中冲""劳宫""大陵""间使""曲泽"穴区局部皮肤组织,制成20μm厚的矢状切片,用荧光免疫组织化学和组织化学方法进行染色,其中SP标记神经纤维,鬼笔环肽用于标记皮肤的各层组织以及血管样结构,然后用荧光显微镜和共聚焦显微镜对所标记的组织标本进行观察和记录。结果:从整体显微结构上看,SP主要标记的是皮肤组织中的细神经纤维。SP阳性表达神经纤维在浅层的表皮和真皮层以游离的单纤维方式存在,在深层的皮下组织中则以神经纤维束的方式存在。通过计数大鼠心包经五输穴各穴区浅层中游离神经纤维的数量和长度,观察到SP阳性表达神经纤维在"中冲"和"劳宫"穴区之间的分布密度差异无统计学意义(P>0.05),在"大陵""间使""曲泽"各穴区之间的分布密度也差异无统计学意义(P>0.05),而SP阳性表达神经纤维在前面2个穴中的分布密度显著高于它们在后面3个穴中的分布密度(P<0.01)。同时,SP阳性表达神经纤维多与血管样结构伴行。结论:本研究表明SP阳性表达神经纤维在大鼠心包经五输穴各穴区皮肤中的分布密度从肢体远端到近端呈减少的趋势,从神经纤维的数量上反映出了不同穴区神经支配的相对特异性。

Objective To investigate the distribution of substance P（SP）-positive nerve fibers in local skin tissues of the five shu-points of the Pericardium Meridian in rats for revealing the differential innervations of the five acupoints.MethodsSix adult male SD rats were used in the present study.Under deep anesthesia,the rats received transcardiac perfusion with 4%polyformaldehyde＋phosphate buffered solution,followed by dissecting the local skin tissues from the sites corresponding to five shu-points＂Zhongchong＂（PC 9）,＂Laogong＂（PC 8）,＂Daling＂（PC 7）,＂Jianshi＂（PC 5）,and ＂Quze＂（PC 3）in the human body.The tissues were sagittally cut into sections（20μm）using a freezing microtome,followed by fluorescent immunohistochemical and histochemical staining with SP,phalloidin and DAPI,respectively.The distribution of SP-positive fibers were observed under fluorescent microscope and laser confocal microscope.Results In general,SP expressed on the thin sensory fibers in the skin tissue.SP-positive nerve fibers distributed in a free single style in the epidermis and dermis,and gathered together to form a bundle in the subcutaneous layer.After counting the number and length of free single fibers in the epidermis and dermis of each of the five shu-points,we found that no significant differences existed in the density between the PC 9and PC 8regions,as well as among the PC 7,PC 5,and PC 3regions（P〉0.05）.In contrast,the density of SP-positive nerve fibers in the former two acupoints（PC 9and PC 8）was significantly higher than that of anyone of the latter three acupoints（P〈0.01）.In addition,SP positive nerve fibers mainly ran in parallel to the vessel-like structure.Conclusion The local skin tissues of acupoint PC 9,PC 8,PC 7,PC 5,and PC 3of the Pericardium Meridian express SP-positive fibers,which presents a decreasing tendency in the density from the distal to the proximal part of the forelimb,reflecting a relative specificity of the innervations of the five shu-points.