神经干注射阿霉素对三叉神经脊束核内P物质的影响

Influence of adriamycin locally injected into infraorbital nerve on substance - P in lateral nucleus caudalis spinalis nervi trigemini in adult rats

目的探讨成年大鼠眶下神经束注射阿霉素对三叉神经脊束核尾侧区内P物质的影响。方法用0．5％的阿霉素溶液直接注射于一侧眶下神经束，对侧注射生理盐水作自身对照，分别在给药后3d、1周、2周、3周、4周、5周、6周在光镜和电镜下观察双侧三叉神经节的变化；并用免疫组化方法观测三叉神经尾侧脊束核内（CNV）P物质（SP）免疫阳性颗粒的灰度值。结果阿霉素给药后，电子显微镜下观察到实验侧三叉神经节细胞形态改变，胞内出现大量空泡，神经纤维髓鞘发生变性、弯曲、增厚、分离；实验侧三叉神经尾侧脊束核内（CNV）P物质（SP）免疫阳性颗粒灰度值明显高于对照侧（P〈0．01），不同时间组之间SP含量差异无统计学意义。结论眶下神经束注射阿霉素能够选择性破坏相应的节细胞，减少CNV区SP含量。SP作为一种重要的神经递质，其合成或释放异常可能与三又神经痛的发病有关，其在三叉神经痛的发作机制中具有重要的作用。

Objective To observe the influence of adriamycin applied locally to infraorbital nerve on the substance P in the lateral nucleus caudalis spinalis nervi trigemini in adult rats. Methods 0. 5% adriamycin was directly injected into the infraorbital nerve on one side, and normal saline in the opposite as control. The trigeminal ganglions were observed under electro - microscope at 3,7,14,21,28,42 days respectively after local administration of adriamycin and normal saline in both groups. Substance P （SP） like positive immuuoreactive granules in the lateral nucleus caudalis spinalis nervi trigenlini （CNV） on both sides were examined by immunohistochemical method. Results Degenerated trigeminal ganglion cells were found in adriamycin treated nelwes ,while myelinated fibers remained intact. The grey scale value of SP like positive immunoreactive granules in the experimental side was markedly less than that on control side （ P 〈 0. 01 ）, while no significant difference was present between the groups in different duration. Conclusion Adriamycin locally administered can produce selective destruction of trigeminal ganglion cells,and can reduce the levels of SP in regions of CNV. As an important neurotransimitter,substance P,its synthesis and release is possibly related to the pathogenesis of trigeminal neuralgia and plays significant role in its onset. The results suggested that local administration of adriamycin is of promising therapeutic implications, further to lay a relevant theoretical foundation in clinical management of trigeminal neuralgia.