星状神经节阻滞对福尔马林致痛兔脊髓背角c-fos基因表达的影响

目的 :观察星状神经节阻滞 (SGB)对福尔马林致痛兔脊髓背角c -fos基因表达的影响 ,探讨其治疗疼痛的可能机制。方法 :在星状神经节阻滞模型建立 1周后 ,1 9只日本大耳白兔随机分为 3组 :假手术组 (A组 ) 5例、SGB组 (B组 )和对照组 (C组 )各 7例。A组麻醉后灌注固定取脊髓颈段 6～ 8;B组和C组在皮下注射福尔马林 1h后 ,B组经导管注入 0 .2 5 %布比卡因 0 .5ml,C组用等量的生理盐水。观察 1h后灌注固定取脊髓。用免疫组织化学方法检测脊髓背角Fos含量的变化。结果 :B组和C组刺激侧脊髓背角内可见大量的Fos阳性神经元。Fos阳性神经元主要集中分布于背角Ⅰ、Ⅱ层。但两组间Fos的OD值无明显差别 (P >0 .0 5)。而对侧脊髓和A组内未见或偶见少量Fos阳性神经元。结论 :皮下注射福尔马林可引起兔脊髓背角c-fos基因的表达 ,但星状神经节阻滞对其无明显影响

Effect of Stellate Ganglion Block on Expression of c-fos Gene in Spinal Cord of Rabbits Following Formalin Stimulation

Objective To investigate the effect of stellate ganglion block (SGB) on expression of c-fos gene in spinal cord of rabbits following formalin stimulation and its therapy of pain.Methods One week after institution of stellate ganglion block model, nineteen healthy rabbits were randomly divided into three groups: sham operation group (group A, n=5), SGB group (group B, n=7) and control group (group C, n=7). In group B and group C, 3% formalin 0.2 ml was injected into intraplantar of the right paw. Pain response was observed. 1 hour after using formalin, 0.25% bupivacaine 0.5 ml and normal saline 0.5 ml were injected through the catheter in group B and C, respectively. The effect of SGB was conformed by ptosis and miosis. Rabbits were deeply anesthetized and fixed 1 h after using bupivacaine or normal saline, and spinal cord of cervical 6～8(C 6～8 ) were removed. The expression of c-fos gene protein product (Fos)-positive neurons was displayed by immumohistochemistry technique of strept avidin biotin enzyme complex (SABC).Result Fos-positive neurons were distributed mainly in the ipsilateral laminaⅠand Ⅱ of dorsal horn of spinal cord following formalin stimulation in group B and group C, but the OD of Fos showed no difference in the two groups( P >0.05); whereas none or few were detected in the contralateral dorsal horn and in group A.Conclusion There are expression of c-fos gene in superficial layers of the spinal dorsal horn in rabbits following formalin stimulation, but it is not affected by SGB.