电刺激肌筋膜激痛点模型大鼠局部微血管再生与血浆内皮素1及一氧化氮的表达

Effect of electrical stimulation on local microvessel regeneration and expression of plasma endothelin-1 and nitric oxide in a rat model of myofascial trigger points

背景:电刺激具有促进局部组织血管再生和调节血管活性物质表达的作用,但电刺激是否能促进肌筋膜激痛点局部组织血管再生和血流状态改变尚无研究报道。目的:探讨电刺激对肌筋膜激痛点局部组织微血管再生和血浆内皮素1及一氧化氮的影响。方法:将54只SD大鼠随机分为正常对照组、模型组和电刺激组,每组18只。模型组和电刺激组采用打击联合离心运动法建立肌筋膜激痛点模型,电刺激组大鼠给予肌筋膜激痛点电刺激干预(参数:直刺2 mm,电压强度6 V,频率20 Hz,脉冲宽度160 ms),干预30 min/次,1次/d,干预15 d。分别于干预前及干预7,15 d,每个时间点每组取6只大鼠,在肌筋膜激痛点局部取材,制片后进行苏木精-伊红和免疫组织化学染色,光镜下观察其病理变化,并进行微血管密度计数分析。采用ELISA检测血浆中内皮素1及一氧化氮表达水平。实验方案中有关动物伦理问题已经南方医科大学南方医院实验动物伦理委员会讨论批准。结果与结论:(1)镜下可见:造模后肌筋膜激痛点局部组织呈现虫蚀样脆性改变;经电刺激干预后局部组织微血管增加,组织结构逐渐恢复;(2)微血管密度计数:干预前模型组、电刺激组较正常对照组偏低;干预7,15d电刺激组显著高于其他2组(均P<0.01),电刺激组组内比较显著高于前一时间点;正常对照组和模型组各时间点组内比较差异均无显著性意义(P>0.05);(3)血浆内皮素1与一氧化氮水平:干预前模型组、电刺激组内皮素1与一氧化氮水平较正常对照组高,干预15 d电刺激组较前内皮素1水平降低(与0 d和7 d比较均P<0.01),干预7,15 d电刺激组一氧化氮水平持续增加(与前一时间点比较均P<0.01);正常对照组和模型组各时间点组内比较差异均无显著性意义(P>0.05);(4)结果表明:电刺激干预能够促进肌筋膜激痛点局部组织微血管再生,并能调节肌筋膜激痛点局部组血管活性物质的表达,改善肌筋膜激痛点局部组织缺血、缺氧状态而促进局部组织修复。

BACKGROUND:Plenty of evidences have revealed that electrical stimulation(ES)can promote local tissue vascular regeneration and regulate the expression of vasoactive substances,but it is unclear whether ES may promote local revascularization and change blood flow state in myofascial trigger points(MTrPs)or not.OBJECTIVE:To investigate the effect of ES on microvascular regeneration and plasma endothelin-1 and nitric oxide levels in MTrPs.METHODS:Fifty-four Sprague-Dawley rats were randomly divided into blank control,model and ES groups,with 18 rats in each group.And each group was equally subdivided into three subgroups(before,7 and 15 days after intervention).In the model and ES groups,the rat model of MTrPs was established using combat and eccentric motion.Once the MTrPs model was made,the ES group was given ES intervention(depth:2 mm,voltage:6 V,frequency:20 Hz,pulse width:160 ms)at MTrPs,30 minutes per day,for 15 days.Six rats from each group were executed at 7 and 15 days of intervention.Paraffin sections were manufactured for hematoxylin-eosin and immunohistochemical staining after the local tissues of MTrPs were dissected and separated.Subsequently,pathological changes were observed under light microscope.Microvessel density was counted and analyzed.The levels of plasma endothelin-1 and nitric oxide were detected by ELISA.The study protocol was approved by the Experimental Animal Ethics Committee of the Nanfang Hospital of Southern Medical University in China.RESULTS AND CONCLUSION:The changes of brittleness and insect-likes erosion in local MTrps tissues were observed under the light microscope in the model and ES groups.The micro-vessel density in MTrps increased and the tissue structure of MTrps gradually returned to be normal after ES intervention.The microvessel density in the model and ES groups was lower than that in the blank control group before intervention,but the microvessel density in the ES group was significantly higher than that in the other two groups at 7 and 15 days of intervention(both P<0.01).In the ES group,the microvessel density was significantly increased with time after intervention.There was no statistically significant difference between the blank control and model group(P>0.05).The levels of plasma endothelin-1 and nitric oxide were higher in the model and ES groups than the blank control group before intervention.After 15 days of intervention,the levels of plasma endothelin-1 in the ES group were decreased(P<0.01,vs.0 and 7 days),while the level of nitric oxide was slightly increased at 7 and 15 days of intervention(P<0.01,vs.the former time point).There was no statistically significant difference between the blank control and model groups(P>0.05).These results reveal that ES intervention can promote the regeneration of microvessels and regulate the expression of vasoactive substances in MTrPs tissue,improve ischemia and hypoxia state of MTrPs and contribute greatly to local tissue repair.