按法刺激肌筋膜激痛点模型大鼠局部对TRPV1的影响

Effect of Local Pressing Stimulation on TRPV1 of Myofascial Trigger Point in Rats

目的研究按法刺激激痛点是否通过激活辣椒素受体1(transient receptor potential vanillic acid subtype 1,TRPV1)进而产生效应,初步探讨按法止痛的作用机制。方法60只SD大鼠随机分为空白组10只和造模组50只,空白组不进行造模和干预操作,仅正常饲养;造模组以局部击打配合离心跑台法建立大鼠慢性激痛点模型。造模成功后,将40只成模大鼠再随机分为模型组、按法组、按法+抑制剂组、按法+溶剂组,每组10只。模型组不进行干预;按法组给予局部按法治疗;按法+抑制剂组给予腹腔注射辣椒平溶液(TRPV1抑制剂)和局部按法治疗;按法+溶剂组给予腹腔注射溶剂和局部按法治疗。按法操作由自制按法仪器进行。取材后以免疫组化法检测TRPV1;以酶联免疫吸附法测定内皮型一氧化氮合酶(endothelial nitric oxide sgnthase,eNOS)、一氧化氮(nitric oxide,NO)和五羟色胺(5-hydroxytryptamine,5-HT)含量。结果(1)与空白组相比,模型组TRPV1平均光密度值增高(P<0.05);与模型组相比,按法组和按法+溶剂组TRPV1平均光密度值增高(P<0.05),按法+抑制剂组平均光密度值仅有数值降低但差异无统计学意义(P>0.05);与按法组和按法+溶剂组相比,按法+抑制剂组TRPV1平均光密度值降低(P<0.05)。(2)与空白组相比,模型组NO和eNOS含量增高(P<0.05);与模型组相比,按法组、按法+抑制剂组和按法+溶剂组的NO和eNOS含量增高(P<0.05);与按法组和按法+溶剂组相比,按法+抑制剂组的NO和eNOS含量降低(P<0.05)。(3)与空白组相比,模型组5-HT含量增高(P<0.05);与模型组相比,按法组、按法+抑制剂组和按法+溶剂组的5-HT含量降低(P<0.05);与按法组和按法+溶剂组相比,按法+抑制剂组的5-HT含量升高(P<0.05)。结论按法刺激激痛点产生去活化效应,其机制可能与激活TRPV1受体、上调eNOS和NO含量、降低5-HT含量有关。

Objective To investigate whether transient receptor potential vanillic acid subtype 1(TRPV1)could be activated by stimulation of myofascial trigger point(MTrP)by the pressing and to preliminary explore the mechanism of analgesia by pressing.Methods 60 SD rats were randomly divided into blank group(n=10)and model-establishment group(n=50).The blank group did not carry out modeling and intervention,but only fed normally.In the model-establishment group,the model of MTrP was established by local hitting combined with eccentric running.After the evaluation of the model,the model rats were randomly divided into model group,pressing group,pressing+inhibitor group and pressing+solvent group,with 10 rats in each group.The model group did not intervene.The pressing group was given local pressing treatment.Pressing+inhibitor group was given intraperitoneal injection of capsaicin solution(TRPV1 inhibitor)and local pressing treatment.The pressing+solvent group was given intraperitoneal injection of solvent and local pressing treatment.The pressing operation was carried out by a self-made pressing instrument.After sampling,the TRPV1 was detected by immunohistochemical method.The endothelial nitric oxide sgnthase(eNOS),nitric oxide(NO)and 5-hydroxytryptamine(5-HT)were detected by enzyme-linked immunosorbent assay.Results(1)Compared with the blank group,the average optical density of TRPV1 in the model group was significantly higher(P<0.05).Compared with the model group,the average optical density of TRPV1 in the pressing group and pressing+solvent group increased(P<0.05),while the average optical density of the pressing+inhibitor group was only decreased,but the difference was not statistically significant(P>0.05).(2)Compared with the blank group,the content of NO and eNOS in the model group increased(P<0.05).Compared with the model group,the content of NO and eNOS in the pressing group,pressing+inhibitor group and pressing+solvent group increased(P<0.05).Compared with the pressing group and pressing+solvent group,the content of NO and eNOS in the pressing+inhibitor group decreased(P<0.05).(3)Compared with the blank group,the content of 5-HT in the model group was significantly higher(P<0.05).Compared with the model group,the content of 5-HT in the pressing group,pressing+inhibitor group and pressing+solvent group decreased(P<0.05).Compared with the pressing group and the pressing+solvent group,the content of 5-HT in the pressing+inhibitor group was increased(P<0.05).Conclusion The deactivation effect of MTrP by the pressing may be related to the activation of TRPV1 receptor,up-regulation of eNOS and NO content and decrease of 5-HT content.