电针对CFA致炎性痛大鼠脊髓ATF-2Thr71位点磷酸化的干预研究

目的:观察电针的镇痛效应及其对脊髓背角活化转录因子2(ATF-2)苏氨酸71(Thr71)位点活化的干预作用。方法:实验分为空白对照组(N组)、模型对照组(CFA组)和电针治疗组(EA组)。CFA组和EA组通过足内注射弗氏完全佐剂(CFA)建立大鼠炎性痛模型,EA组于造模后1d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1、3和14d的足缩腿阈(PWTs),及患侧脊髓背角磷酸化ATF-2(p-ATF-2)(Thr71)阳性细胞数。结果:与N组相比,于造模后各时段,CFA组大鼠PWTs显著降低(P0.05),p-ATF-2(Thr71)阳性细胞数增多(P0.01);造模后3、14d时,EA组大鼠PWTs显著高于同期CFA组(P0.01),而p-ATF-2(Thr71)阳性细胞数则明显少于同期CFA组(P0.05)。结论:电针抗炎性痛作用与抑制脊髓背角ATF-2(Thr71)的磷酸化密切相关。

Intervention of electroacupuncture on phosphorylation of spinal ATF-2 at Thr71 site in rats with CFA-induced inflammatory pain

Objective: To observe the analgesic effect of electroacupuncture(EA) and its intervene on the activation of ATF-2 at Thr71 in spinal cord dorsal horn of rats.Methods: All 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 0.1ml Complete Freund’s Adjuvant(CFA) into right hindpaw of rats in CFA and EA group.EA(dilatational wave,2/100Hz,1mA for 15 min,2mA for 15 min) was applied to bilateral ’Zusanli’(ST 36) and ’Kunlun’(BL 60) for 30min,once per day.The paw withdrawal thresholds(PWTs) were measured by using Dynamic Plantar Aesthesiometer 37450before CFA-injection(as Base) and at 1d,3d,14d after CFA-injection.The number of phospho-ATF-2(Thr71) positive cells in lumbar spinal cord dorsal horn(SCDH) were detected by immuno-histochemistry at 3d,14d after CFA-injection.Results: Compared with N group,PWTs of rats in CFA group were decreased markedly at 1d,3d,14d after CFA-injection(P<0.05),and the number of p-ATF-2(Thr71) positive cells of ispilateral SCDH in CFA group began to increase at 3d post-injection(P<0.01),maintained until 14d post-injection(P<0.01).PWTs in EA group were higher obviously than those in CFA group at 3d,14d after CFA-injection(P<0.01).Moreover,the numbers of p-ATF-2(Thr71) positive cells of ispilateral SCDH were significantly less than those in CFA group at same time point(P<0.01).Conclusion: Inhibiting phosphorylation of ATF-2 at Thr71 site in SCDH of CFA rats maybe a new mechanism of EA analgesia.