针灸对肌筋膜疼痛综合征大鼠炎症因子及脊髓OX-42、BDNF表达影响

Effects of Acupuncture and Moxibustion on Inflammatory Factors and Expressions of OX-42 and BDNF in Spinal Cord of Rats with Myofascial Pain Syndrome

目的观察毫针刺和温和灸对肌筋膜疼痛综合征(myofascial pain syndromes,MPS)大鼠血清炎症因子和脊髓小胶质细胞及脑源性神经营养因子(brain-derived neurotrophic factor,BDNF)的影响,对比针刺和艾灸的作用是否具有差异性。方法32只SPF级SD大鼠随机分为空白组、模型组、艾灸组、针刺组,每组各8只。除空白组外,其余采用钝性打击联合离心运动法复制MPS大鼠模型。艾灸组和针刺组以激痛点为施治部位,每日治疗15 min,连续治疗7 d,模型组与空白组不予治疗。分别于造模前及治疗前后,采用热刺痛仪检测痛阈值(thermal withdrawal latency,TWL);肌电仪检测大鼠激痛点自发电位情况;HE染色法观察大鼠股内侧肌病理形态变化;酶联免疫吸附法检测大鼠血清白细胞介素-8(interleukin-8,IL-8)和前列腺素E2(prostaglandin E2,PGE2)表达水平;免疫组化法检测大鼠脊髓背角小胶质细胞标记物OX-42表达;蛋白免疫印迹法检测大鼠脊髓BDNF蛋白表达;RT-PCR技术检测大鼠脊髓OX-42基因表达水平。结果与空白组相比,模型组大鼠造模后及治疗后TWL均明显降低,自发电活动明显,骨骼肌排列紊乱炎症浸润明显,IL-8、PGE2、OX-42和BDNF蛋白表达上调(P<0.01)。与模型组相比,艾灸组和针刺组治疗后TWL升高,自发电活动减少,肌组织形态明显改善,IL-8、PGE2、OX-42和BDNF蛋白表达下调(P<0.05,P<0.01),其中艾灸组在改善IL-8、PGE2表达方面优于针刺组(P<0.01)。结论传统毫针刺、温和灸可以缓解MPS大鼠疼痛,减少激痛点自发电活动,促进股内侧肌组织损伤恢复,其消炎镇痛机制可能与降低血清IL-8及PGE2水平,抑制脊髓小胶质细胞OX-42活化和BDNF表达有关,且针刺与艾灸抗炎镇痛作用存在一定差异性。

Objective To observe the effects of filiform needle acupuncture and mild moxibustion on serum inflammatory factors,spinal microglia,and brain derived neurotrophic factor(BDNF)in rats with myofascial pain syndrome(MPS),and compare the differences in the effects of acupuncture and moxibustion.Methods 32 SPF grade SD rats were randomly divided into blank group,model group,moxibustion group,and acupuncture group,with 8 rats in each group.Except for the blank group,the MPS rat model was replicated using blunt impact combined with centrifugal exercise method.The moxibustion group and acupuncture group were treated at the pain point for 15 min daily for 7 consecutive days.The model group and blank group were not treated.Before modeling and before and after treatment,thermal withdrawal latency(TWL)was measured using a hot prick pain instrument;Detection of spontaneous potentials at pain points in rats using electromyography;HE staining was used to observe the pathological changes in the medial femoral muscle of rats;Enzyme linked immunosorbent assay was used to detect the expression levels of IL-8 and PGE2 in rat serum;Immunohistochemical method was used to detect the expression of OX-42,a microglial cell marker in the dorsal horn of the rat spinal cord;Protein immunoblotting was used to detect the expression of BDNF protein in the spinal cord of rats;RT-PCR technology was used to detect the expression level of OX-42 gene in the spinal cord of rats.Results Compared with the blank group,the model group rats showed significant decrease in TWL after modeling and treatment,with significant self generating activity,disordered skeletal muscle arrangement and inflammatory infiltration.The expression of IL-8,PGE2,OX-42,and BDNF proteins were upregulated(P<0.01).Compared with the model group,the moxibustion group and acupuncture group showed increase in TWL,decrease in self generating activity,and significant improvement in muscle tissue morphology.The expression of IL-8,PGE2,OX-42 and BDNF proteins were downregulated(P<0.05 or P<0.01),and moxibustion group was superior to the acupuncture group in improving the expression of IL-8 and PGE2(P<0.01).Conclusion Traditional filiform needle acupuncture and mild moxibustion can alleviate pain in MPS rats,reduce the self generating activity of pain points,promote the recovery of tissue damage in the medial femoral muscle.Its anti-inflammatory and analgesic mechanism may be related to reducing serum IL-8 and PGE2 levels,inhibiting the activation of OX-42 in spinal microglia and the expression of BDNF.