肉毒毒素A对大鼠慢性神经源性疼痛镇痛作用的研究

Study on Analgesic Effect of Botulinum Toxin in Chronic Neuropathic Pain in Rats

目的观察肉毒毒素A(BoNT-A)对L5、L6脊神经结扎引起慢性神经源性疼痛模型大鼠行为学的影响。方法建立Wistar大鼠左侧L5、L6脊神经结扎模型(SNL模型)。SNL模型大鼠随机分为3组(n=8)。1)实验组:SNL术后第3天同侧足底皮下注射BoNT-A30U/kg;2)对照组:SNL术后同侧足底皮下注射相同容积生理盐水;3)假手术组:仅暴露而不结扎L5和L6脊神经。均分别测定术前、给药前、给药后1d、3d、5d、7d、14d、21d的机械缩足反射阈值(MWT)和热缩足反射潜伏期(TWL)。结果实验组手术同侧足底皮下注射BoNT-A可以增加大鼠的MWT和TWL,实验组手术对侧、对照组、假手术组应用BoNT-A对MWT和TWL无影响。结论足底皮下注射BoNTA能够改善SNL模型大鼠手术同侧肢体的MWT和TWL,有镇痛作用。

Objective In a spinal nerve ligation model （ SNL model）, we observed the effects of botulinum toxin A （ BoNT- A） on rats＇ behaviors. Methods The SNL model was established on the left L5, L6 of Wistar rats. SNL model rats were ran- domly distributed into three groups （ n = 8 ）. （ 1 ） Experimental group ： Ipsilateral plantar subcutaneous BoNT-A injection was implemented （30 U / kg） 3 days after SNL operation ; （2） Control group ： Ipsilateral plantar subcutaneous saline injec- tion was implemented （30 U / kg） 3 days after SNL operation ; （3） Pseudo-operation group ： Exposure but no ligation of the L5 or L6 spinal nerves was eondueted. Both MWT （mechanical withdrawal threshold） and TWL （thermal withdrawal laten- cy） were measured in each group,also,before operation,before BoNT-A injection,and 1/3/5/7/14/21 days after BoNT-A injection ,respectively. Results Ipsilateral plantar subcutaneous BoNT-A injection increased both MWT and TWL in experi- mental group rats. Neither MWT nor TWL was affected in eontralateral plantar BoNT-A injection group, control group, or pseudo-operation group. Conclusion Plantar subeutaneous BoNT-A injection can improve ipsilateral extremital MWT and TWL in SNL model rats. Thus,we suggested that BoNT-A might have analgesic effect.