电针小海与下巨虚穴对DU模型大鼠ChAT及α7 nAchR的影响

Effect of Electroacupuncture at Points Xiaohai and Xiajuxu on ChAT and α7 nAchR in a Rat Model of DU

目的观察电针十二指肠溃疡(duodenal ulcer,DU)模型大鼠小海、下巨虚对大鼠血清肿瘤坏死因子-a(tumour necrosis factor-a,TNF-a)、血清乙酰胆碱转移酶(choline acetyltransferase,Ch AT)及十二指肠组织烟碱型乙酰胆碱受体α7(neuronal acetylcholine receptorsα7,α7 nAchR)等表达的影响,初步探讨"合治内府"中"合"穴的相对特异性。方法将40只健康SD大鼠随机分为空白组(A组)、模型组(B组)、小海组(C组)和下巨虚组(D组),每组10只。于大鼠右臀部皮下部注射10%盐酸半胱胺建立大鼠DU模型,造模成功后,C组电针小海穴,D组电针下巨虚穴。肉眼观察各组大鼠十二指肠组织溃疡并评分,采用双抗体夹心酶联免疫吸附测定(ELISA)法检测大鼠血清中TNF-a表达,用可见紫外分光光度计进行比色,测量大鼠血清中Ch AT的表达,蛋白质印迹法(western blot)检测大鼠十二指肠组织中α7 nAchR的表达。结果造模后,B组、C组和D组大鼠十二指肠溃疡评分较A组显著增高(均P<0.01),C组、D组评分显著低于B组(均P<0.01),且D组显著低于C组(P<0.01)。B组TNF-a表达较A组显著增高(P<0.01),C组、D组TNF-a显著低于B组(均P<0.01),且D组显著低于C组(P<0.01)。C组Ch AT表达较B组有升高趋势但无统计学意义(P>0.05),D组Ch AT表达明显高于B组(P<0.01),且高于C组(P<0.05)。与B组相比,C组和D组α7 nAchR表达显著增高(均P<0.01)。各组Ch AT与α7 nAchR表达呈显著的正相关(r=0.444,P=0.007)。结论电针小海、下巨虚均能降低DU大鼠血清中十二指肠溃疡评分及TNF-a的表达,升高血清中Ch AT与十二指肠组织中α7 nAchR的表达,说明电针对十二指肠溃疡产生治疗作用有可能是通过调节TNF-a等来实现的,其机制有可能是通过激活胆碱能抗炎通路产生抗炎作用来完成的。D组效果优于C组,提示下巨虚存在相对特异性。

Objective To investigate the effect of electroacupuncture at points Xiaohai and Xiajuxu on the expressions of tumour necrosis factor-a（TNF-a） and choline acetyltransferase（Ch AT） in serum and nicotinic acetylcholine receptor α7（α7 nAchR） in duodenal tissues in a rat model of duodenal ulcer（DU） and preliminarily explore the relative specificity of He-Sea point in ＂treating visceral diseases with He-Sea point＂. Methods Forty healthy SD rats were randomized into blank（A）, model（B）, Xiaohai（C） and Xiajuxu（D） groups, 10 rats each. A rat model of DU was made by subcutaneous injection of 10% cysteamine hydrochloride at the right buttock. After successful model making, group C was given electroacupuncture at point Xiaohai and group D, at point Xiajuxu. Duodenal tissue ulcer was macroscopically observed and scored in every group of rats. Rat serum expression of TNF-a was determined by double antibody sandwich enzyme-linked immunosorbent assay（ELISA）; rat serum expression of Ch AT, by ultraviolet spectrophotometry colorimetry; rat duodenal expression of a7 nAchR, by Western blot. Results After model making, the duodenal ulcer score was significantly higher in groups B, C and D than in group A（all P〈0.01） and significantly lower in groups C and D than in group B（both P〈0.01） and in group D than in group C（P〈0.01）. TNF-a expression was significantly higher in group B than in group A（P〈0.01） and significantly lower in groups C and D than in group B（both P〈0.01） and in group D than in group C（P〈0.01）. Ch AT expression tended to increase in group C compared with group B but there was no statistically significant difference（P〈0.05） and was significantly higher in group D than in group B（P〈0.01） or C（P〈0.05）. a7 nAchR expression was significantly higher in groups C and D than in group B（both P〈0.01）. There was a positive correlation between Ch AT and a7 nAchR expressions in every group（r=0.444, P=0.007）. Conclusions Electroacupuncture at both points Xiaohai and Xiajuxu can reduce the duodenal ulcer score and serum TNF-a expression and increase serum Ch AT and duodenal a7 nAchR expressions in DU rats. The results show that the therapeutic effect of electroacupuncture on duodenal ulcer may be produced by regulating TNF-a. Its mechanism may be activating cholinergic anti-inflammatory pathway to produce an anti-inflammatory effect. The effect being better in group D than in group C suggests that Xiajuxu has the relative specificity.