坐骨神经内注射阿霉素对家兔背根神经节的化学切除术作用

Chemical dorsal root ganglionectomy by intra-sciatic nerve injection of adriamycin in rabbits

目的研究坐骨神经内注射阿霉素对家兔背根神经节(DRG)的化学切除术作用。方法家兔48只,右侧坐骨神经内注射1％阿霉索0．2 ml,左侧注射等量生理盐水。给药后4、24 h荧光显微镜观察阿霉素荧光表达；给药后1～8周光镜和电镜观察脊髓前角神经元和DRG的形态学及超微结构。给药后连续观察家兔下肢感觉和运动功能。结果给药后24 h,阿霉素荧光在右侧DRG内表达；给药后1～8周光镜显示右侧DRG细胞变性、坏死、消失,神经胶质细胞增生。给药后2周电镜显示右侧DRG细胞内呈现线粒体、核糖体、内质网等重要细胞器溶解,多处髓磷体形成及溶酶体聚积。与给药前比较,给药后1～2周右侧后肢热痛阈降低,给药后4～8周右侧后肢热痛阈升高(P＜0．05),给药后1～8周家兔双侧下肢运动功能无障碍。结论家兔坐骨神经内注射1％阿霉素0．2ml有DRG化学切除术作用。

Objective To investigate the effects of chemical dorsal root ganglionectomy by injection of adriamycin into sciatic nerve. Methods Forty-eight adult rabbits weighing 2.0-2.5 kg were used in this study. 1% adriamycin 0.2 ml was injected into the fight sciatic nerve while 0.9% saline 0.2 ml was injected into the left sciatic nerve under general anesthesia. Fluorescence microscope was used to detect adriamycin at 4 and 24 h after injection. Light and electron microscope were used to examine the neurons in the anterior horn of spinal cord and dorsal root ganglion （DRG）. Furthermore the sensory and motor function of the hind limbs were evaluated before and 1-8 weeks after injection. Results Fluorescence microscopic study revealed well-distributed fluorescence dye stained adriamycin in fight DRG at 24 h after injection. Light microscopic examination revealed degeneration, necrosis and disappearance of cells and hyperplasia of gliacytes in right DRG at 1-8 weeks after injection. Electron microscopic study showed lysis of mitochondria, ribosome and endoplasmic reticulum and the accumulation of myehn and lysosomes in right DRG cells 2 weeks after injection. Threshold to noxious thermal stimuli of the fight hindlimb at 1-2 weeks after injection was significantly lower than the baseline before injection and became higher than the baseline at 3-8 weeks after injection （ P 〈 0.05 ） . Conclusion 1% adriamycin 0.2 ml injected into sciatic nerve can produce chemical dorsal root ganglionectomy.