弗氏佐剂致炎大鼠脊髓背角Fos神经元的表达

目的探讨完全弗氏佐剂（CFA）致炎性痛大鼠Fos神经元（Fos-LIN）在脊髓背角痛觉传导通路中的表达及意义。方法①16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,观察注射前后大鼠热缩足反射潜伏期TWL的变化;②48只大鼠随机平分为两组后分别注射NS和CFA（剂量和注射部位同前）以免疫组化法检测脊髓背角Fos-LIN表达。结果①大鼠注射CFA后TWL逐渐降低,12h时为最低点,持续3d后逐渐恢复,14d时基本恢复至基础水平;②NS组脊髓背角Fos-LIN散在出现,而CFA组中Fos-LIN1h时最先出现在大鼠右侧脊髓背角I-II层,4h时出现在V-VI层的数目逐渐增多,12h时为脊髓全层出现最多,至14d时在背角各层少见,且同组左侧脊髓各层Fos-LIN在1h-14d均比较少见。结论50μlCFA能诱导大鼠产生为期2周的炎性痛觉过敏。炎症期间脊髓背角Fos神经元的持续表达与外周痛觉信号的传导和中枢的调控有关。

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

Objective To study the expression of Fos neurons in transmission of nociceptive information in dorsal horn of spinal cord in CFA-induced inflammatory hyperalgesic rats.Methods ①16 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）before and after s.c injection.②48 adult male SD rats were randomly divided into two groups（n=24）,After NS or CFA injection,immunohistochermical staining was used to detect the expression of Fos neurons in the dorsal horn neurons of spinal cord.Results ①TWL of CFA group shorten significantly at 4 h（P〈0.01）,reached the valley-bottom at 12 h and improved gradually since 3th day,restored to the initial level on 14th day.②The Fos-LIN（Fos-like immunoreactive neurons）mainly distributed in the superficial layers（Ⅰ-Ⅱ）and laminaⅤ,Ⅵ of the dorsal horn on the ipsilateral side of the CFA injection（P〈0.01）.Conclusion The expression of Fos neurons that accompanied with hyperalgia are related to the transmission of nociceptive information and the control of central system.