姜黄素对神经病理性疼痛大鼠脊髓背角和背根神经节GR和NMDAR-NR1表达的影响

目的探讨姜黄素对神经病理性疼痛大鼠脊髓背角和背根神经节皮质激素受体(GR)和NMDAR-NR1表达的影响。方法将雄性SD大鼠72只(体质量220～250g),随机分成4组:假手术组(Sham组)、慢性坐骨神经结扎损伤组(CCI组)、CCI+溶剂组(SC组)、CCI+姜黄素100mg/kg组(Cur100组)。SC组和Cur100组大鼠在坐骨神经结扎后,分别腹腔注射溶剂或100mg.kg-1.d-1姜黄素,至术后14d。于术前2d和术后1、3、5、7、10、14d测定机械缩足反射阈值(MWT)和热缩足反射潜伏期(TWL);术后3、7、14d取大鼠术侧L4、L5脊髓背角和背根神经节,用免疫组化法检测脊髓背角和背根神经节GR和NMDAR-NR1表达情况。结果与Sham组相比,CCI组术后TWL、MWT明显降低(P<0.01),术侧脊髓背角和背根神经节内GR和NMDAR-NR1表达明显增多(P<0.01)。与CCI组相比,Cur100组大鼠TWL和MWT明显提高(P<0.05),脊髓背角和背根神经节GR和NMDAR-NR1表达明显减少(P<0.05)。结论姜黄素可通过抑制脊髓背角和背神经根节GR和NMDAR-NR1的表达而减轻CCI大鼠神经病理性疼痛。

Effects of curcumin on expression of GR and NMDAR-NR1 in posterior horn and dorsal root ganglia of rats with neuropathic pain

Objective To explore the effects of curcumin on expression of glucocorticoid receptor(GR) and NMDAR-NR1 in posterior horn and dorsal root ganglia of rats with neuropathic pain.Methods 72 male SD rats,weighing 220-250 g,were randomly divided into four groups:sham operation group(sham group),chronic constriction injury(CCI) group,CCI+solvent group(SC group) and CCI+curcumin 100 mg/kg group(Cur100 group).After sciatic nerve ligation,rats in SC group and Cur100 group were subjected to intraperitoneal injection of solvent or curcumin 100 mg·kg-1·d-1,respectively,until 14 days after operation.Mechanical withdrawal threshold(MWT) and thermal withdrawal latency(TWL) of rats were measured 2 days before operation and 1,3,5,7,10 and 14 days after operation.L4,L5 posterior horn and dorsal root ganglia of rats on the operative side were chosen 3,7 and 14 days after operation,and immunohistochemistry was used to detect the expression of GR and NMDAR-NR1 in posterior horn and dorsal root ganglia of rats.Results Compared with the sham group,TWL and MWT decreased markedly(P<0.01),while expression of GR and NMDAR-NR1 in posterior horn and dorsal root ganglia on the operative side increased significantly(P<0.01) after operation in CCI group.Compared with CCI group,TWL and MWT increased markedly(P<0.05),while expression of GR and NMDAR-NR1 in posterior horn and dorsal root ganglia decreased significantly(P<0.05) in Cur100 group.Conclusion Curcumin may reduce neuropathic pain of rats with CCI via inhibition the expression of GR and NMDAR-NR1 in posterior horn and dorsal root ganglia.