摘要
目的:观察电针(EA)"足三里"-"阳陵泉"镇痛的累积效应,及大鼠下丘脑和海马细胞蛋白激酶A(PKA)活性的变化。方法:Wistar雌鼠68只,随机分为正常对照组、慢性压迫损伤(CCI)组、CCI+EA 2天(d)组、CCI+EA 2周(w)组、去卵巢(OVX)+CCI组、OVX+CCI+EA 2 d组、OVX+CCI+EA 2 w组。Morris水迷宫法检查OVX+D-半乳糖皮下注射动物的学习记忆能力。结扎坐骨神经造成CCI慢性痛模型,电针双侧"足三里"-"阳陵泉"穴(2/15 Hz,1~2 mA,1次/d)。用辐射热照射大鼠双侧足底引起的缩腿反应潜伏期(PWL)的差值作为痛敏分数(HS)判断动物的痛反应;用免疫组化法检测下丘脑和海马组织PKA的活性。结果:CCI术后,与正常组比较,各组HS都明显升高。在单纯CCI动物上,与CCI组比,CCI术后第18天CCI+EA 2 d、CCI+EA 2 w的HS显著减小(P<0.05);CCI+EA 2 w组的HS显著低于CCI+EA 2 d组(P<0.05)。在记忆损害的动物上,OVX+CCI+EA 2 w和OVX+CCI+EA 2 d组HS明显低于OVX+CCI组(P<0.05);而两EA组间HS差异没有显著性意义(P>0.05)。CCI+EA 2 w组下丘脑室旁核(PVN)、弓状核(ARC)和视上核(SON)区PKA的灰度值均明显低于正常对照组(P<0.05),PVN和ARC区也显著低于CCI+EA 2 d组(P<0.05);OVX+CCI+EA 2 w组PVN和SON区的PKA灰度值亦均明显低于OVX+CCI组(P<0.05)。说明EA 2 w可上调PKA的表达,且具有累积性作用。OVX+CCI+EA 2 w组ARC和SON区PKA的灰度值均显著高于CCI+EA 2 w组(P<0.05),提示EA上调PKA表达的累积效应在记忆功能减退的动物上明显减弱。海马PKA的表达与SON等下丘脑核团PKA的表达趋势类似。结论:电针镇痛有累积作用,其累积效应可能与下丘脑、海马细胞PKA的表达上调有关,并且与动物神经记忆有密切关系。
Objective To observe the accumulative analgesic effect of electroacupuncture（EA）and the simultaneous changes of protein kinase A （PKA） expression in hypothalamus and hippocampus in rats with chronic constrictive injury （CCI） or/ and learning-memory impairment. Methods Sixty-eight female Wistar rats were randomized into normal control, CCI, CCI＋ EA 2 d, CCI＋EA 2 w, OVX＋CCI, OVX＋CCI＋ EA 2 d and OVX＋CCI＋EA 2 w groups, with 10 cases in each except OVX＋ CCI group （n =8）. CCI pain model was established by ligature of the right sciatic nerve with surgical suture. EA （2/15 Hz, 1-2 mA, 30 min） was daily applied to bilateral ＂Zusanli＂ （ST 36） and ＂Yanglingquan＂ （GB 34） for 2 days （2 d） and 2 weeks （2 w） respectively. Neuro-memory impairment was induced by OVX plus subcutaneous injection of D-galactose. Hyperalgesic scores （HS） were detected with radiation-heat irradiation and PKA activity was detected by immunohistochemical method. Results After CCI, HS of all groups increased significantly in comparison with normal control group （P〈0.05）. In simple CCI rats, compared with CCI group, HS of both CCI ＋ EA 2 d and CCI ＋ EA 2 w groups decreased markedly （P〈0.05）, and that of CCI ＋ EA 2 w group was evidently lower than that of CCI＋ EA 2 d group on the 18th day after CCI （P〈0.05）. In memory impairment rats, HS of both OVX＋ CCI ＋ EA 2 d and OVX＋ CCI ＋ EA 2 w groups was significantly lower than that of OVX＋ CCI group （P〈0.05） ; and no significant difference was found between OVX＋ CCI ＋ EA 2 w and OVX＋ CCI ＋ EA 2 d groups in HS （P^0.05）. Results of immunohistochemistry showed that the integral grey values （IGV） of PKA of paraventricular nucleus （PVN）, arcuate nucleus （ARC） and supraoptic nucleus （SON） of hypothalamus in CCI＋ EA 2 w group were significantly lower than those in normal control and CCI＋ EA 2 d groups （P〈0.05）. IGV of PVN and SON in OVX ＋ CCI ＋ EA 2 w group were also markedly lower than those in OVX＋CCI group （P〈0.05）, displaying upregulation and cumulative increase of PKA expression by EA 2 w. IGV of PKA, ARC and SON in OVX＋ CCI ＋ EA 2 w group were markedly higher than those in CCI ＋ EA 2 w group （P〈0.05）, suggesting an apparent attenuation of the cumulative upregulation effect of PKA expression after learning-memory injury. The changing tendency of PKA expression in hippocampal CA 1 region was similar to that of SON after repeated EA of ST36 and GB34. Conclusion Repeated EA has a cumulative analgesic effect in CCI rats, which is probably related to its resultant upregulation of PKA expression in neurons of hypothalamus and hippocampus and the animals＇ neuro-memory.
出处
《针刺研究》
CAS
CSCD
2008年第2期80-87,共8页
Acupuncture Research
基金
国家自然科学基金资助项目(C03050309)
关键词
针刺镇痛
累积效应
下丘脑
海马
PKA表达
Acupuncture analgesia
Cumulative effect
Hypothalamus
Hippocampus
PKA expression
