大鼠脊髓P物质受体定位分布的免疫细胞化学研究

用免疫细胞化学技术对大鼠脊髓和脊神经节内Ｐ物质受体的定位分布进行了系统的研究。结果证明，Ｐ物质受体阳性胞体和树突主要密集地分布于脊髓全长的Ⅰ层，此外，还发现Ⅱ层的外侧部出现少量阳性胞体和树突，来自Ⅲ层的阳性树突穿过Ⅱ层后进入Ⅰ层；Ⅲ～Ⅳ和Ⅹ层也可见中等密度的阳性胞体和树突；Ⅵ层和Ⅶ层仅见少量阳性胞体和树突，但胸髓中间带外侧核、骶髓副交感运动核、骶髓后连合核内可见大量浓染的阳性胞体和树突；Ⅷ、Ⅸ层、Ｏｎｕｆ氏核、外侧颈核和外侧脊索核也有阳性胞体和树突．灰质内的阳性胞体的树突还伸向前索和外侧索，有时可达脊髓的边缘．此外，脊神经节内也可见少量散在且均匀分布的小型阳性胞体．

IMMUNOCYTOCHEMICAL LOCALIZATION OF SUBSTANCE P RECEPTOR IN THE SPINAL CORD OF THE RAT

Substance P(SP) is one of the well-known peptides, distributes widely in the nervous system and has a lot of important effects, especially involves in the processing of nociceptive information in the peripheral nervous system and plays an important role in antinociception in the central nervous system. In order to identify the precise targets of SP, the immunocytochemical method was used in the present study to systemically localize SP,eceptor (SPR) in the rat spinal cord and spinal dorsal root ganglion. SPR-like immunoreactive (SPR-LI) products were found on the membrane of neuronal somata and dendrites. There were darkly and lightly stained neuronal cell bodies and dendrites, the former were mainly observed in the superficial laminae of the dorsal horn, thoracic intermediolateral nucleus, sacral parasympathetic nucleus and Onuf's nucleus, the latter were mainly seen in the deeper laminae of the dorsal horn, ventral horn and spinal dorsal root ganglion. SPR-LI neuronal cell bodies and dendrites were densely Observed in the entire length of lamina i. A few SPR-LI neuronal cell bodies and dendrites were found in outer part of lamina Ⅱ , only a few SPR-LI dendrites of lamiha Ⅲ neurons passing lamina Ⅱ and entered laminaⅠ. There were quite dense SPR-LI neuronal cell bodies and dendrites in laminae Ⅲ Ⅴ and Ⅹ. SPR-LI neuronal cell bodies and dendrites were sparsely found in the lamina Ⅵ and Ⅶ, but a large number of darkly stained SPR-LI neuronal cell bodies and dendrites were encountered in the thoracic intermediolateral nucleus, sacral parasympatbetic nucleus and sacral dorsal commissural nucleus. Larger or smaller neuronal cell bodies and dendrites were observed in the laminae Ⅷ and Ⅸ or Onuf's nucleus. SPR-LI dendrites of the gray matter neurons entered the anterior or lateral funiculus of the white matter, some of them reached the margin of the spinal cord. SPR-LI neuronal somata and dendrites were also found in the lateral cervical nucleus and lateral spinal nucleus. Some SPR-LI neuronal cells were sparsely seen in the spinal dorsal root ganglion. The present results indicated that the localization of the SPR in the spinal cord matched quite well with the distribution of SP-LI fibers and terminals.