长段神经液氮冷冻预防大鼠残端神经瘤形成过程中脊髓后角P物质变化

Changes of Substance P in the substantia gelatinosa of the dorsal horn field after liquid nitrogen freezing of severed nerve for prevention of terminal neuroma

目的本实验旨在探讨长段神经液氮冷冻预防大鼠残端神经瘤形成脊髓后角P物质变化。方法20只大鼠切断双侧坐骨神经,左侧神经残端液氮冷冻(12±2)mm,右侧设为对照侧,观察20周及28周,采用光镜组织学方法进行评价,SP法免疫组织化学染色检查脊髓后角P物质变化并进行图像分析。结果20例对照侧均有坐骨神经瘤形成,而神经残端经冷冻处理后未见神经瘤形成,冷冻侧P物质的分布范围及部分区域的密度明显低于对照侧,图像分析及统计学分析显示光密度及染色面积均有显著差异(P<0.05)。结论长段神经液氮冷冻预防残端神经瘤形成的过程中脊髓后角P物质的明显减少可能说明神经瘤性伤害性刺激可促使脊髓后角P物质的释放。

Objective To determine the changes of Substance P in the substantia gelatinosa of the dorsal horn field after transient liquid nitrogen freezing of severed rat sciatic nerve for prevention of terminal neuroma. Methods The bilateral sciatic nerves of 20 SD rats were severed, and the left sciatic nerves was subjected to transient liquid nitrogen freezing with the right sciatic nerve as control. After 20 and 28 weeks, the nerve ends were resected and prepared for microscopic examination, and Substance P in the substantia gelatinosa of the dorsal horn field was determined by immunohistochemistry. Results Typical neuromas occurred in the severed ends of the right sciatic nerves but not in the left sciatic nerves. The distribution and optical density of Substance P in the substantia gelatinosa of the dorsal horn field was significantly smaller in the left than in the right nerves （P〈0.05）. Conclusion Liquid nitrogen freezing of the severed sciatic nerve results in decreased release of Substance P in the substantia gelatinosa of the dorsal horn field, suggesting that noxious stimulation may increase Substance P release in the substantia gelatinosa of the dorsal horn field.