耳电针缓解功能性消化不良大鼠胃部高敏的效应规律及对神经生长因子的影响

Effect laws of ear electroacupuncture in relieving gastric hypersensitivity in rats with functional dyspepsia and its effect on nerve growth factor

目的观察耳电针在降低功能性消化不良(FD)大鼠胃部高敏感性中的作用规律,并探讨其对神经生长因子(NGF)的影响。方法①实验一:将16只10 d龄SD雄性幼鼠随机分为对照组和耳电针组,每组8只。耳电针组幼鼠通过三硝基苯磺酸灌肠诱导FD胃部高敏模型,第8周龄时选取双侧耳穴“胃”穴进行连续5 d电针刺激;对照组幼鼠仅给予生理盐水灌肠。分别记录2组大鼠第8周龄干预前颈部斜方肌肌电积分、腹部回撤反射评分和耳电针组大鼠单次耳电针后、5次耳电针后及耳电针结束后第3,5,10天颈部斜方肌肌电积分,分析耳电针的即时效应、累加效应和维持效应。②实验二:将40只10 d龄SD雄性幼鼠随机分为对照组、模型组、耳电针组、电针对照组,每组10只。除对照组外,其余组幼鼠通过三硝基苯磺酸灌肠诱导FD胃部高敏模型。第8周龄时,耳电针组选取双侧耳穴“胃”穴、电针对照组选取双侧耳垂进行连续5 d电针刺激。干预结束后处死各组大鼠,HE染色观察各组胃底及远端结肠的病理改变,ELISA法检测血浆去甲肾上腺素(NE)水平,RT-PCR和Western blot法检测胃底NGFmRNA和蛋白表达情况。结果①耳电针组大鼠第8周龄电针前胃部球囊扩张压力为60和80 mmHg时的肌电积分和腹部回撤反射评分均显著高于对照组(P均<0.05)。胃部球囊扩张压力为60和80 mmHg时,单次耳电针后的肌电积分均明显低于第8周龄电针前(P均<0.05),5次耳电针后的肌电积分均明显低于单次耳电针后(P均<0.05),耳电针结束后第3天的肌电积分与5次耳电针后比较差异均无统计学意义(P均>0.05),耳电针结束后第5天的肌电积分仍明显低于第8周龄电针前(P均<0.05),耳电针结束后第10天的肌电积分与第8周龄电针前比较差异均无统计学意义(P均>0.05)。②各组大鼠胃底、结肠HE染色均未见明显炎症反应。模型组和电针对照组大鼠血浆NE水平、胃底组织中NGF mRNA和蛋白相对表达量均明显高于对照组(P均<0.05),耳电针组大鼠血浆NE水平、胃底组织中NGF mRNA和蛋白相对表达量均明显低于模型组和电针对照组(P均<0.05)。结论耳电针可有效缓解功能性消化不良大鼠胃部高敏,多次干预效果更显著,且有一定的维持效应,其镇痛机制可能与调控血浆NE和胃底NGF表达有关。

Objective It is to observe the laws of ear electroacupuncture in reducing gastric hypersensitivity in rats with functional dyspepsia(FD),and to explore its effect on nerve growth factor(NGF).Methods①Experiment I:Sixteen 10-day-old male SD rats were randomly divided into control group and ear electroacupuncture group,with 8 rats in each group.The young rats in the ear electroacupuncture group were given trinitrobenzene sulfonic acid by enema to induce FD gastric hypersensitivity models.The EMG scores of cervical rhomboid muscle and abdominal retraction reflex scores of the rats at the 8 th week of age in the two groups before the intervention,and the EMG scores of cervical rhomboid muscle of rats in the ear acupuncture group after once ear acupuncture,5 times ear acupuncture and on the 3 rd,5 th and 10 th day after the end of ear acupuncture were recorded respectively,to analyze the immediate,cumulative and maintenance effects of ear acupuncture.②Experiment II:Forty 10-day-old male SD rats were randomly divided into control group,model group,ear electroacupuncture group and electroacupuncture control group,with 10 rats in each group.The FD gastric hypersensitivity model was induced by enema with trinitrobenzene sulfonic acid in the pups of all groups except the control group.At the age of 8 weeks,the ear acupuncture group selected bilateral ear acupuncture points“stomach”and the control group selected bilateral ear lobes for 5 d of continuous electroacupuncture stimulation.After the intervention,the rats in each group were executed,and the pathological changes of gastric fundus and distal colon were observed by HE staining,plasma norepinephrine(NE)level was measured by ELISA,and mRNA and protein expression of gastric fundic nerve growth factor(NGF)were detected by RT-PCR and Western blot.Results①The EMG scores and abdominal retraction reflex scores of the rats in the ear electroacupuncture group were significantly higher than those in the control group at 60 and 80 mmHg of gastric balloon dilatation pressure before ear electroacupuncture at the 8 th week of age(P<0.05).The EMG scores after once ear electroacupuncture were significantly lower than those before electroacupuncture at the 8 th week of age at gastric balloon dilatation pressures of 60 and 80 mmHg(all P<0.05),the EMG scores after 5 times ear electroacupuncture were significantly lower than those after once(all P<0.05),the differences between the EMG scores on the 3 rd day after the end of the ear electroacupuncture and after 5 times ear electroacupuncture were not statistically significant(all P>0.05),and the EMG scores on the 5 th day after the end of the ear electroacupuncture were still significantly lower than those before ear electroacupuncture at the 8 th week of age(all P<0.05),and the differences between the EMG scores on the 10th day after the end of the ear electroacupuncture and those before the electroacupuncture at 8 th week of age were not statistically significant(all P>0.05).②No obvious inflammatory reaction was found in HE staining of stomach fundus and colon of rats in each group.The level of plasma NE and the relative expression of NGF mRNA and protein in the gastric fundus tissue of rats in the model group and the electroacupuncture control group were significantly higher than those in the control group(all P<0.05),the level of plasma NE and the relative expression of NGF mRNA and protein in the gastric fundus tissue of rats in the ear electroacupuncture group were significantly lower than those in the model group and the electroacupuncture control group(all P<0.05).Conclusion Auricular electroacupuncture can effectively relieve the gastric hypersensitivity in rats with functional dyspepsia,and the effect of multiple interventions is more significant,and has a certain maintenance effect.Its analgesic mechanism may be related to the regulation of the expression of NE in plasma and NGF in gastric fundus.