慢性疼痛保留性神经损伤模型两种建立方法比较

Comparison of two methods for establishment of spared nerve injury model of chronic neuropathic pain

目的通过改进大鼠保留性神经损伤(spared nerve injury,SNI)疼痛模型,将大鼠单侧腓总神经结扎后,比较离断与不离断大鼠腓总神经的痛阈值差异。方法选择30只健康雄性SD大鼠,随机分为结扎离断组(A组)、结扎未离断组(L组)和假手术组(C组),每组10只。A组和L组分别用丝线对大鼠右侧腓总神经进行结扎离断和单纯结扎,C组只暴露右侧腓总神经但不进行任何处理。建模后于不同时间点测量各组大鼠机械刺激缩足痛阈值(mechanical withdrawal threshold,MWT)和热刺激缩足痛阈值(thermal withdrawal threshold,TWT)。结果结扎离断和结扎未离断腓总神经均能引起大鼠痛阈的降低,至术后7 d降至最低,其后趋于平稳(P<0.05)。A组和L组的MWT[(2.33±0.36)g和(4.40±0.75)g vs(11.80±4.43)g]和TWT[(33.50±1.29)ms和(36.75±1.26)ms vs(46.75±4.50)ms]显著低于与C组,差异均有统计学意义(P均<0.05),且A组较L组更明显。结论通过结扎离断大鼠右侧腓总神经建立的SNI模型较结扎未离断建立的模型能更为明显地降低痛阈。

Objective To compare the pain threshold difference in spared nerve injury(SNI)model with or without amputating peroneal nerve after ligating it.Methods Thirty healthy male SD rats were randomly divided into three groups,ligation and amputation group(group A,n=10),ligation group(group L,n=10)and sham group(group C,n=10).In group A,the right peroneal nerve was amputaed after ligated by silk.In group L,the right peroneal nerve was simply ligated by silk.However,in group C,the right peroneal nerve was only exposed without any treatment.Mechanical withdrawal threshold(MWT)and thermal withdrawal threshold(TWT)of all rats were measured at different time points after modeling.Results The pain threshold of group A and group Ldecreased significantly over time(P<0.05)and tended to be stable from the seventh day after the operation.At the postoperative 7 day,compared with group C,MWT([2.33±0.36]g and[4.40±0.75]g vs[11.80±4.43]g)and TWT([33.50±1.29]ms and[36.75±1.26]ms vs[46.75±4.50]ms)of group A and group L were significantly lower(P<0.05,respectively),and the pain threshold of group A was significantly lower than that of group L.Conclusion Compared with the SNI model established only by ligating peroneal nerve,the pain threshold of the SNI model established by ligating and amputating peroneal nerve decreases significantly.