摘要
目的:观察电针对痛觉敏化诱发大鼠机械性刺激缩足反应阈值(MPWT)和热刺激缩足反应潜伏期(TPWL)及背根神经节(DRG)内蛋白酶激活受体2(PAR 2)蛋白含量的影响,探讨电针干预痛觉敏化诱发的背根神经节PAR 2机制。方法:第1部分:SD大鼠随机分为假敏化诱发组和敏化诱发组,用于MPWT检测的假敏化诱发组为5只,敏化诱发组为6只,用于TPWL检测的每组均8只。于大鼠左后足足底皮下注射1%角叉菜胶100μL(第1次注射),7d后于该足背注射100ng/25μL前列腺素E2(第2次注射)建立痛觉敏化诱发模型。假敏化诱发组于第1次注射100μL的生理盐水,其余同痛觉敏化诱发模型。检测造模前,第1次注射后5h及3、6d,第2次注射后0.5、4、24h的大鼠造模侧足跖MPWT和TPWL。第2部分:SD大鼠随机分为假敏化诱发组、敏化诱发组、假电针组和电针组,每组16只。造模方法同第1部分。电针组于第1次注射后开始电针双侧"足三里"和"昆仑"穴,1次/d,共7d。检测同第1部分相同时间点大鼠造模侧足跖MPWT和TPWL;用酶联免疫吸附法检测第2次注射后24h造模侧DRG内PAR 2蛋白含量。结果:第1部分:与假敏化诱发组比较,敏化诱发组大鼠第1次注射后5h,第2次注射后4、24h造模侧MPWT及TPWL明显降低(P<0.01,P<0.05)。第2部分:与敏化诱发组比较,电针可显著提高第2次注射后4、24h的MPWT及第1次注射后3d、第2次注射后4、24h造模侧的TPWL(P<0.01,P<0.05),而假电针无此作用。与假敏化诱发组比较,敏化诱发组大鼠造模侧腰(L)4-L 6DRG中PAR 2含量升高(P<0.05);与敏化诱发组比较,电针组大鼠造模侧L 4-L 6DRG中PAR 2含量降低(P<0.05),而假电针组无明显变化。结论:电针治疗可阻断痛觉敏化诱发的发生,促使MPWT、TPWL升高,可能与下调DRG中PAR 2蛋白表达相关。
Objective To observe the effect of electroacupuncture （EA） on mechanical hyperalgesia threshold （MHTs） and thermal hyperalgesia threshold （THTs） and content of proteinase-activated receptors 2 （PAR 2） in dorsal root ganglia （DRG） in rats with inflammatory pain, so as to explore its peripheral mechanism underlying improvement of inflammatory pain. Methods The present study contains two parts. 1） In the first part, 27 male SD rats were randomized into sham hyperalgesic priming （sham- HP） group and real hyperalgesic priming （HP） group （n=5 in the sham-HP group and n=6 in the HP group for the test of MHTs, n =8 in the two groups for the test of THTs）. The sham-HP model was established by subcutaneous injection of normal saline into the left plantar part of the hind-paw, and the HP model established by subcutaneous injection of 1% carragenan （the first injection） into the same left hind paw, followed by injection of PGE2 （100 ng/25 μL, the second injection） into the dorsum pedis of the same hind paw 7 days after the first injection. The ipsilateral paw withdrawal latencies （MHTs and THTs） were detected before and 5 h, 3 d and 6 d after the first injection, 0.5, 4 and 24 h after the second injection. 2） in the second part, 64 male SD rats were randomly divided into sham-HP, HP, sham-EA and EA groups （n = 16 in each group）. The sham-HP and HP models were made in the same way as the first part. Both＂Zusanli＇（ST 36）and ＂Kunlun＇（BL 60） were punctured with filiform needles in the sham-EA group and also stimulated with EA.. 2 Hz/100 Hz, 0.5- 1.5 mA （0.5 mA increase per 10 rain） for 30min in the EA group, 1 time/d for 7 d. Both ipsilateral MHTs and THTs were observed at the same time-points of the first part and the PAR 2 protein content in the L 4-L 6 DRGs was assayed by ELISA 24 h after the second injection. Results 1） In the first part of the study, compared with the sham-HP group, the MHTs at 5 h and 3 d, and THT at 5 h after the first injection, and MHTs, and THTs at 4 and 24 h after the second injection were significantly decreased in the HP group （P〈0.01, P〈0.05）. 2） In the second part of the study, compared with the HP group, the MHTs at 4 and 24 h after the second injection and the THTs at 3 d after the first injection, 4 and 24 h after the second injection were significantly up-regulated in the EA group （P〈0.01, P〈0.05）. The content of PAR 2 in the DRGs （L 4- L 6） was significantly higher in the HP group than in the sham-HP group （P〈0.05）, but considerably lower in the EA group than in the HP group （P〈0.05）. Conclusion EA can suppress hyperalgesia priming in inflammatory pain rats which may be related to its effect in down-regulating PAR 2 level in the lumbar DRGs.
出处
《针刺研究》
CAS
CSCD
北大核心
2018年第1期14-19,共6页
Acupuncture Research
基金
国家自然科学基金青年项目(No.81603692
81603690)
浙江省科技厅公益性(实验动物平台)项目(No.2016C37135)
2016年浙江省大学生科技创新活动暨新苗人才计划资助项目(No.2016R410005)
浙江省一流学科(中医学)资助(浙政办函[2016]6号)
关键词
电针
炎性痛
痛觉敏化诱发
痛转化
蛋白酶激活受体2
腰背根神经节
Electroacupuncture
Inflammatory pain
Hyperalgesic priming
Pain transformation
Proteinase-activated receptors 2
Lumbar dorsal root ganglia
