加味盆痛灵对子宫内膜异位症疼痛大鼠背根神经节神经元动作电位的影响

Effect of Jiawei Pentongling on Action Potential of Dorsal Root Ganglion Neurons in Rats with Endometriosis Pain

目的观察加味盆痛灵对子宫内膜异位症(EMs)模型大鼠背根神经节(DRG)神经元动作电位的影响,以探讨其抗EMs疼痛的作用机制。方法采用自体内膜移植法构建SD大鼠EMs模型,将造模成功的大鼠随机分为模型、加味盆痛灵组,每组8只。另设假手术组8只。加味盆痛灵组大鼠每天给予加味盆痛灵(7.77g/kg)直肠给药,连续4周。模型组和假手术组直肠给予等体积生理盐水。分别于不同时间点测定大鼠50%缩足阈值(PWT);运用全细胞电流钳技术记录加味盆痛灵对EMs疼痛大鼠DRG神经元兴奋性的影响。结果与假手术组比较,模型组痛阈值降低,动作电位爆发阈值下降,动作电位半峰时程(APD50)延长,300pA去极化电流诱发的动作电位发放频率增加(P<0.01)。与模型组比较,加味盆痛灵组痛阈值上调,动作电位爆发阈值升高,APD50缩短,300pA去极化电流诱发的动作电位发放频率减少(P<0.01)。3组间静息电位水平和动作电位峰值比较,差异无统计学意义(P>0.05)。结论加味盆痛灵抗EMs疼痛的机制可能与抑制DRG神经元的兴奋性相关。

Objective To observe the effect of Jiawei Pentongling(JWPTL)on the action potential of dorsal root ganglion(DRG)neurons in model rats with endometriosis(EMs),thus to study its mechanism of action against pain in EMs.Methods An autologous endometrial transplantation method was used to construct a model of EMs in SD rats,and successfully modeled rats were randomly divided into the model group and JWPTL group,8 rats in each group.A sham-operated group of 8 rats was also set up.The rats in JWPTL group were administered with JWPTL(7.77 g/kg)rectally daily for 4 successive weeks.The rats in the model group and the sham-operated group were administered with equal volume of normal saline rectally.The 50%paw contraction threshold(PWT)was measured at different time points.The whole cell current clamp technique was used to record the effect of JWPTL on the excitability of DRG neurons in rats with EMs pain.Results Compared with the sham-operated group,the pain threshold was down-regulated,the action potential burst threshold decreased,the action potential half-peak duration(APD50)was lengthened,and the frequency of action potential discharges induced by 300pA depolarizing current was increased in the model group(P<0.01).Compared with the model group,the pain threshold was up-regulated,the action potential burst threshold was increased,the APD50 was shortened,and the frequency of action potential discharges induced by 300pA depolarizing current was decreased in JWPTL group(P<0.01).The resting potential levels and peak action potentials were not statistically significant among the 3 groups(P>0.05).Conclusion The mechanism of JWPTL against pain in EMs may be related to the inhibition of excitability of DRG neurons.