鞘内预先应用L-NAME抑制福尔马林炎性痛大鼠脊髓后角c-fos表达  

INTRATHECAL PREADMINISTRATION OF L-NAME REDUCING FORMALIN-EVOKED C-FOS EXPRESSION IN SPINAL DORSAL HORN OF RATS

作　　者：李平 薛富善 何农 孙海燕 李成文 杨泉涌 刘鲲鹏 

机构地区：[1]中国医学科学院整形外科医院麻醉科,北京100041

出　　处：《中国疼痛医学杂志》2008年第1期24-27,共4页Chinese Journal of Pain Medicine

基　　金：中国医学科学院中国协和医科大学优秀青年骨干重点基金资助项目(990013)

摘　　要：目的:观察鞘内预先应用非选择性一氧化氮合酶抑制剂-Nω-硝基-L-精氨酸甲酯(L-NAME)对福尔马林炎性痛大鼠脊髓后角内c-fos表达的影响。方法:选择体重220～310g、鞘内置管后无神经损伤的SD大鼠60只,在其左足底皮下注射4%福尔马林40μl建立炎性痛模型。在皮下注射福尔马林前15min,通过预先置入的导管向大鼠鞘内注射容量均为10μl的L-NAME250μg(FL组)或生理盐水(FN组)。分别在注射后1h、4h、8h、12h和24h处死动物,在每一时间点每组处死的动物数均6只。另有4只大鼠在左足底皮下注射生理盐水,4h后处死作为对照组。采用免疫组化方法观察各组大鼠同侧脊髓后角内c-fos表达的情况。结果:在皮下注射福尔马林后,大鼠脊髓后角内出现了迅疾和持久的c-fos表达增强反应,而且随着时间的推移,脊髓后角深层fos阳性(fos-like immunoreactivity,FLI)神经元数目的增加更加显著。与FN组相比,FL组大鼠脊髓后角内FLI神经元数目在浅层减少23.1%～51.8%,而在深层则减少46.3%～58.3%。结论:鞘内预先应用L-NAME可有效抑制福尔马林炎性痛诱发的脊髓后角c-fos表达增加,尤其是对脊髓后角深层c-fos表达的选择性抑制最为显著。Objective：To observe the effects of intrathecal preadministration of L-NAME,a non-selective NOS inhibitor,on the formalin-evoked c-fos expression in the spinal dorsal horn of rats.Methods：Sixty female SD rats weighing 220～310 g,showing no signs of neurological deficiency after intrathecal catheterization,received subcutaneous injection of formalin 40 μl in the plantar surface of the left hindpaw to establish the inflammatory pain model.15 minutes before formalin test,L-NAME 250 μg or 0.9% normal saline,all in volume of 10 μl,were intrathecally injected through previously inserted catheter.The survival time of animals were 1,4,8,12 and 24 hours after operation,with 6 rats for each manipulation at each time point.In addition,4 other rats were sacrificed 4 hours following subcutaneous injection of normal saline 40 μl and served as control.The c-fos expression in ipsilateral spinal dorsal horn was detected by immunohistochemistry technique.Results：There appeared a rapid and persistent enhancement of c-fos expression in the spinal dorsal horn after subcutaneous injection of formalin.Furthermore,with the time passing by,the increase in the number of fos-like immunoreactivity（FLI） neurons seemed more obvious in the deep laminae of spinal dorsal horn.As compared to FN group,the number of FLI neurons was decreased by 23.1%～51.8% in the superficial laminae and 46.3%～58.3% in the deep laminae of spinal dorsal horn,respectively.Conclusion：Intrathecal preadministration of L-NAME can effectively inhibit formalin-induced c-fos expression in the spinal dorsal horn of rats,especially in the deep laminae.

关 键 词：Nω-硝基-L-精氨酸甲酯 一氧化氮 C-FOS 脊髓 福尔马林试验 

分 类 号：R402[医药卫生—临床医学]