完全弗氏佐剂致炎性痛大鼠脊髓背角Fos蛋白的表达

Expression of Fos protein in dorsal horn neurons of spinal cord in CFA-induced inflammatory pain rats

目的：探讨完全弗氏佐剂（CFA）所致炎性痛大鼠Fos蛋白在脊髓背角痛觉传导通路中的表达及意义。方法：64只SD大鼠随机均分为两组，于右后肢踝关节外侧皮下分别注射0.9％生理盐水（NS）或CFA50μl，每组取8只观察注射前后热缩足反射潜伏期（TWL）的变化；余48只以免疫组化法检测脊髓背角Fos蛋白表达。结果：大鼠注射CFA后TWL逐渐降低，并在12h时达最低点（下降62％），持续3d后缓慢上升，14d时基本恢复至基础水平；NS组脊髓背角Fos蛋白散在表达，而CFA组中1h后Fos蛋白最先在大鼠右侧脊髓背角Ⅰ～Ⅱ层表达（P〈0.01），4h时Ⅴ～Ⅵ层蛋白表达逐渐增多（P〈0.01），12h时脊髓全层蛋白表达最多，至14d时背角各层少见Fos蛋白。结论：50μl CFA能诱导大鼠产生为期2周的炎性痛病程。炎症期间脊髓背角Fos蛋白的持续表达与外周痛觉信号的传导和中枢的调控有关。

Objective： To study the expression of Fos protein in transmission of nociceptive information in dorsal hom of spinal cord in complete Freund＇s adjuvant（CFA） induced inflammatory hyperalgesic rats. Methods：Sixty four adult male SD rats were randomly divided into two groups and were given normal saline （NS） or CFA in a dose of 50 μl subcutaneouly （ s. c） injection in ankle joint of right hind limb. To measure the change of thermal withdrawal latency （TWL） and detect the expression of Fos protein in the dorsal horn neurons of spinal cord with immunohistochermical staining. Results： TWL of CFA group shorten significantly at 4 h, reached the valley bottom at 12 h and improved gradually since 3 th day, restored to the initial level on 14 th day. The Fos protein mainly distributed in the superficial layers（Ⅰ～Ⅱ） and lamina （Ⅴ～Ⅵ） of the dorsal horn on the ipsilateral side of the CFA injection. Conclusion： The expression of Fos protein that accompanied with hyperalgia was related to the transmission of nociceptive information and the control of central system.