钙结合蛋白CR在坐骨神经压榨模型脊髓内的表达

目的：研究大鼠坐骨神经压榨模型的钙结合蛋白Calretinin（CR）在脊髓的时空变化规律，为探讨其在神经再生中的作用提供实验依据。方法：36只SD大鼠随机分为假手术对照组和坐骨神经压榨组，实验组压榨后分别存活1d到21d，免疫组化结合图像分析技术观察CR在脊髓分布和含量的变化。结果：在对照组，CR样阳性神经元主要分布于腰髓背角Ⅰ，Ⅱ层，Ⅲ～Ⅵ层只观察到一些散在分布的CR样阳性神经元，脊髓前角Ⅷ层和Ⅸ层内也可见一些多极的中间型阳性神经元。坐骨神经压榨1d后，分布于腰髓背角H层内的CR样阳性神经元比对照组有轻微增加。3d后，CR样阳性神经元与对照组相比没有明显改变。7d后，CR样阳性神经元有轻微的减少；14d后，CR的表达显著下降；至21d，CR的表达有所恢复，但仍低于7d纽。脊髓后角CR免疫阳性产物灰度值测定结果显示：术后14d后角CR表达最低，与对侧和对照组相比有统计学意义（P〈0．05）。结论：坐骨神经压榨后CR表达变化呈现一定的时空模式，为进一步揭示CR在神经系统疾病中的作用提供实验依据。

Expression of Calretinin in Spinal Cord of Rats Model of Sciatic Nerve Crush

Objective： To study the spatio-temporal pattern of expression of calretinin（CR） in spinal cord and provide experimental evidence of its possible mechanism responsible for regeneration. Methods： A total of 36 SD rats were randomly divided into three groups： sham, control and sciatic crushed Animals in experimental group survived for 1, 3, 7, 14 and 21 days respectively. The distribution and contents of CR in spinal cord was determined by immunohistochemistry and image-analysis. Results： In control animal, CR positive neurons were mainly distributed in lamina I and II of lubar cord. There were only a few CR positive neurons scattered in lamina III-VI, VIII and IX. The number of CR positive neurons was slightly increased at day 1 after the sciatic nerve crush; there was little change at day 3. Slight down-regulation of CR was observed at day 7, but significant change occurred only at day 14. At day 21CR showed a slight increase, but still lower than that at day 7. The measurement of gray density revealed that CR was significantly lower （p 0.005） at day 14 as compared to the groups, control, dayl and day3. Conclusion： Expression of CR demonstrates certain spatio-temporal pattern after sciatic nerve crush,which provides the experimental evidence for further study of role of CR in the diseases of nerve system.