臭牡丹对神经病理性痛大鼠背根神经节N-甲基-D-天冬氨酸受体的影响

Effect of Clerodendrum bungei Steud.on NMDA receptors in dorsal root ganglion of rats with neuropathic pain

目的:探索臭牡丹(Clerodendrum bungei Steud.,CBS)是否通过调控N-甲基-D-天冬氨酸(N-methyl-Daspartate,NMDA)受体缓解坐骨神经分支损伤(Spared nerve injury,SNI)诱导的大鼠神经病理性疼痛。方法:雄性SD大鼠18只,随机分成假手术组(Sham组)、SNI模型组(SNI组)、SNI+CBS治疗组(SNI+CBS组)。各组连续给予30 g·kg^(-1)CBS或等体积生理盐水治疗21 d。PCR方法检测背根神经节(Dorsal root ganglion,DRG)中NMDA受体亚基NR1、GluN2A、GluN2B、GluN3A mRNA表达;Western blot方法检测DRG中GluN2A、GluN2B和IL-10蛋白表达。结果:与Sham组相比,SNI模型大鼠DRG中NR1、GluN2B和GluN3A mRNA表达降低,差异有统计学意义(P<0.05);与SNI组相比,SNI+CBS治疗组NR1、GluN2B和GluN3A mRNA表达升高,各组GluN2A mRNA表达比较差异无统计学意义(P>0.05);与Sham组相比,SNI模型大鼠DRG中GluN2A和GluN2B蛋白水平升高,IL-10蛋白水平下降;与SNI组相比,SNI+CBS组GluN2A和GluN2B降低、IL-10升高,差异均有统计学意义(P<0.05);各组GluN2A的mRNA表达水平差异无统计学意义(P>0.05)。结论:臭牡丹可能通过抑制DRG炎症和调控NMDA受体缓解SNI诱导的大鼠神经病理性疼痛。

Objective:To explore whether Clerodendrum bungei Steud.(CBS)alleviate neuropathic pain of rats induced by spared nerve injury(SNI)through regulating N-methyl-D-aspartate(NMDA)receptors in rats.Methods:Eighteen male SD rats were randomly divided into sham-operation group,SNI group,SNI+CBS treatment group.The rats in each group were treated with 30 g·kg^(-1)CBS or the same volume of normal saline for 21 days.The mRNA expression of NMDA receptor subunits(NR1,GluN2A,GluN2B and GluN3A)in the dorsal root ganglion(DRG)was detected by Real-time quantification PCR.Western blot was used to evaluate protein levels of GluN2A,GluN2B and IL-10 in DRG.Results:Compared with sham group,mRNA expressions of NR1,GluN2B and GluN3A in DRG of SNI model rats were decreased,with statistical significance(P<0.05),which were increased in SNI+CBS group rats.Compared with sham group,the protein levels of GluN2A and GluN2B in DRG of SNI model rats were increased with no statistical significance(P>0.05),while the protein levels of IL-10 were decreased.Compared with SNI group,GluN2A and GluN2B were decreased and IL-10 was increased in SNI+CBS group,with statistical significance(P<0.05).The mRNA expression level of GluN2A in all the groups was with no statistical significance(P>0.05).Conclusion:CBS can alleviate inflammation and regulate NMDA receptor levels in the DRG in SNI,which may be involved in its inhibitory effect on neuropathic pain of rats.