对SNI和CCI两种大鼠神经病理性疼痛模型的实验观察

Experimental observation of SNI and CCI two kinds of rat neuropathic pain models

目的观察并比较大鼠坐骨神经分支选择性损伤(SNI)和慢性坐骨神经压迫损伤(CCI)两种神经病理性模型引起疼痛的效果。方法 Wistar大鼠30只,随机分为3组:Sham组(n=10)、SNI组(n=10)和CCI组(n=10)。Sham组仅暴露坐骨神经后缝合皮肤,分别制作SNI模型和CCI模型,于术前及术后28d内测定大鼠术侧机械疼痛阈值,并于术后第14天和第28天行Western Blotting检测大鼠背根神经节(DRG)内疼痛相关基因三磷酸环化水解酶1(GCH1)的表达变化。结果 Sham组大鼠术后未见疼痛敏感症状,SNI组和CCI组大鼠疼痛阈值于术后第1天较Sham组显著降低(P<0.05),SNI组疼痛阈值直至术后第28天都维持在较低水平,而CCI组痛阈值于术后第3天起才趋于稳定,术后21d开始痛敏症状有所缓解。Western Blotting检测显示,术后第14天SNI组和CCI组GCH1表达均高于Sham组(P<0.05),术后第28天CCI组GCH1表达有所降低,与SNI组出现显著性差异(P<0.05)。结论相比传统CCI模型,SNI模型是一种更敏感、更稳定的神经病理性疼痛模型。

Objective To observe and compare the efficacy of 2 neuropathic pain models： spared nerve injury model （SNI） and chronic constriction injury of sciatic nerve model （CCI）.Methods 30 Wistar rats were dividedrandomly into 3 groups ： sham group （n= 10）, SNI group （n= 10）, and CCI group （n= 10 ）. In the sham group, the sciatic nerves of rats were just surgically exposed,and the SNI model and CCI model were operated on the rightposterior limb. The mechanical withdrawal threshold （MWT） were tested from the lth day preoperative to the 28th day postoperative,and GTP cyclohydrolase 1 （GCH1）, which is a kind of pain-related gene, in dorsal root gan-glion was measured by Western blotting on the 14th and 28th days postoperative.Results The rats in sham group did not appear hyperalgia. MWT in both SNI group and CCI group were obviously declined on the lth day postoper-ative compared with Sham group （P〈0.05）. MWT of SNI rats keeped a low level to the 28th day postoperative, but MWT in CCI group rose again from the 21th day postoperative. The results of Western blotting showed that,onthe 14th day after the operation, the expression of GCH1 in both SNI and CCI group increased compared with sham group （P〈0.05） ,but on the 28th day it decreased in CCI group,and there were statistical differences comparedwith SNI group （P〈0.05）. Conclusion Compared with CCI model,SNI model is a more sensitive and stable neuropathic pain model.