电针“扶突”穴对颈部切口痛大鼠脊髓痛敏物质P物质及镇痛物质5-羟色胺1A受体等表达的影响

Effects of Electroacupuncture at "Futu" (LI 18) on the Immunoactivity of Substance P,5-HT1 AR,etc.of the Cervical Spinal Dorsal Horn in Rats with Neck Incision Pain

目的:观察电针双侧"扶突"穴对甲状腺区切口痛大鼠脊髓背角痛敏物质及镇痛物质表达的影响,探讨针刺镇痛行甲状腺手术的机制。方法:Wistar雄性大鼠随机分为正常组、模型组、扶突穴组、足三里-阳陵泉组,每组10只。沿大鼠颈中线做长约1.5 cm的纵行切口,制作切口痛模型。电针双侧"扶突""足三里"-"阳陵泉"穴30 min。用辐射热测大鼠切口部位热痛阈;用免疫组织化学方法检测颈段(C1-C4)脊髓背角P物质(SP)、速激肽受体-1(NK-1)、环氧合酶-1(COX-1)、5-羟色胺1 A受体(5-HT1 AR)、5-HT2 AR的活性,图像分析仪测定上述物质免疫反应阳性产物的积分灰度值。结果:与颈部切口术前比较,各组的热辐射躲避潜伏期明显缩短(P<0.05);电针"扶突"穴后,与本组术后比较其躲避潜伏期显著延长(P<0.05);电针"足三里"-"阳陵泉"与本组术后比较,躲避潜伏期的差异无统计学意义(P>0.05)。颈部切口术后,脊髓背角浅层SP、NK-1、COX-1的灰度值均明显低于正常组(P<0.05),即表达显著升高;与模型组比较,扶突穴组SP、NK-1、COX-1的灰度值显著升高(P<0.05),表达明显下调;足三里-阳陵泉组与模型组比较,该3项指标差异无统计学意义(P>0.05)。术后,与正常组比较,模型组5-HT 1 AR灰度值明显降低(P<0.05),5-HT2 AR灰度值变化不明显(P>0.05);与模型组比较,扶突穴组5-HT1 AR、5-HT2 AR灰度值明显下降(P<0.05),而足三里-阳陵泉组的灰度值无明显变化(P>0.05)。结论:电针"扶突"穴可缓解大鼠颈部急性切口痛,该作用与其下调脊髓背角SP、NK-1、COX-1的免疫活性,上调5-HT1 AR、5-HT2AR的表达密切相关。

Objective To observe the effect of electroacupuncture（EA） of bilateral ＂Futu＂ （LI 18） on the immunoactivity of substance P （SP）, NK-1 receptor （R）, cyclooxygenase-1 （COX-1）, 5-HT 1 AR and 5-HT2 AR in the cervical spinal dorsal horn of rats with neck incision pain, so as to explore its underlying mechanism in relieving incision pain. Methods A total of 40 Wistar rats were randomly divided into control, model （incision pain）, EA-Futu（LI 18）, and EA-Zusanli（ST 36）-Yanglingquan （GB 34, EA-ST 36-GB 34） groups （n = 10/ group）. A 1.5 cm longitudinal incision was made along the middle of the neck in pentobarbital-anesthetized rats. Pain threshold （PT） was measured using radiant heat. EA （1 -2 mA, 2 Hz/15 Hz） was applied to bilateral LI 18, ST 36-GB 34 for 30 min. The expression of SP, NK-1 R, COX-1, 5-HT 1AR and 5-HT2 AR in the spinal cord （C1 - C4） tissue were detected with immunohistochemistry. Results After the operation, the thermal PT was decreased obviously in comparison with normal control group （P〈0.05）. Oompared with pre-operation, the PT of EA-Futu （LI 18） group increased markedly after treatment （P〈0.05）, and no significant changes were found in PT in EA-ST 36-GB 34 group （P〉0.05）. The immunoactivity of SP, NK-1 R, COX-1 in the superficial dorsal horn in model group was increased significantly and that of 5-HT 1 AR and 5-HT 2 AR significantly and mildly, separately compared with control group （P〈0.05）. In comparison with model group, the immunoreactivity of SP, NK-1 R and COX-1 was decreased considerably, and that of 5-HT 1 AR and 5-HT 2 AR was upregulated remarkably in EA-L118 group （P〈0.05）. No significant changes were found in the immunoactivity of SP, NK-1 R, COX-1, 5-HT 1 AR and 5-HT 2 AR in EA-ST 36-GB 34 group （P〉0.05）. Cenclusion EA-Futu （LI 18） can significantly suppress pain reaction of neck incision in the rat, which is closely associated with its effects in downregulating the expression of SP, NK-1 R, COX-1 and upregulating that of 5-HT 1 AR and 5-HT 2 AR in the spinal dorsal horn.