电针对CFA大鼠脊髓背角CREB的DNA结合活性影响研究

目的:观察电针对CFA大鼠脊髓背角环磷腺苷反应元件结合蛋白(CREB)的DNA结合活性的干预作用以探讨电针的镇痛机制。方法:清洁级健康雄性SD大鼠按完全随机分为空白对照组(N组),模型对照组(CFA组)和电针治疗组(EA组),CFA组和EA组大鼠通过足底内注射弗氏完全佐剂(CFA)建立炎症痛模型,EA组大鼠于造模后5.5 h选取双侧"足三里"、"昆仑"穴进行电针治疗。分别观察造模前、造模后5 h、6 h、2 d、7 d和14 d六个时点的足跖容积和痛阈(PWTs),及造模后6 h、2 d和14 d患侧脊髓背角CREB的DNA结合活性。结果:与N组大鼠比较,造模后各时间点,CFA组大鼠足跖显著肿胀,PWTs明显降低,CREB的DNA结合活性增加;造模后各时间点,EA组大鼠PWTs均显著高于同期CFA组,CREB的DNA结合活性减少,但足跖容积未见明显改变。结论:电针具有良好的镇痛作用,且其镇痛作用可能与调节脊髓背角CREB的DNA结合活性相关。

Electroacupuncture Inhibiting cAMP Response Element Binding Protein DNA Binding Activity in Spinal Cord Dorsal Horn in A CFA Rat Model

Objective ： To investigate whether the mechanism of electroacupuncture （EA） - induced antinociception was related to intervention in spinal cAMP response element binding protein （CREB） DNA binding activity in Complete Freund＇ s Adjuvant （CFA） - induce inflammatory pain model. Methods ： Healthy male Sprague Dawley rats were randomly divided into normal group （N group）, model group （CFA group） and electroacupuncture group （EA group）. Inflammatory pain model was established by injecting subcutaneously with 0.1 mL Complete Freund Adjuvant （CFA） into right hindpaw of rats in CFA and EA groups. EA （dilatational wave,2/100Hz, lmA for 15 min,2mA for 15 min） was applied to bilateral Zusanli （ST 36） and Kunlun （BL 60） for 30 min at 5.5 h after CFA injection. The paw withdrawal thresholds （PWTs） and paw volume were measured before CFA injection （as base） and at 5 h,6 h,2 d,7 d and 14 d after CFA injection. DNA of CREB binding activity in ipsilateral spinal cord dorsal horn （SCDH） was detected by electrophoretic mobility shift assay （EMSA） at 6 h,2 d and 14 d after CFA injection. Results： Compared with N group, paw of rats were obviously swollen, PWTs were decreased markedly. In CFA group, DNA of CREB binding activity was increased in spinal cord dorsal horn,at every detective time point after CFA injection. Compared with CFA group, PWTs in EA group were significantly enhanced at different time points, while, paw volume had no remarkable change. Meanwhile, DNA of CREB binding activity was less than those in CFA group at same time point. Conclusion： EA has a good analgesic effect, which may be related with EA regulating CREB DNA binding activity in spinal cord dorsal horn.