比较电针"合谷""足三里"穴对IBS模型大鼠结肠动力及结肠M3受体表达的影响

目的观察并比较电针"合谷""足三里"穴对肠易激综合征(IBS)模型大鼠结肠动力及结肠M_3受体免疫反应物阳性表达的影响,初步探讨电针不同穴性及不同神经节段支配的穴位对IBS的效应差异及结肠动力改变的相关机制。方法选取新生wistar大鼠40只,随机分为空白对照组、模型对照组、合谷组和足三里组。除空白对照组外,均采用新生期母婴分离、醋酸灌肠及结直肠扩张刺激(CRD)的方法联合制备IBS大鼠模型。大鼠9周龄时,合谷组和足三里组分别给予电针(EA)干预,隔日1次,共5次。空白对照组及模型对照组不予干预。治疗结束后,按照Bristol大便分类法观察电针前后IBS大鼠的便型,采用腹部回撤反射(AWR)对大鼠进行肠道敏感性及平滑肌收缩强度评估,观察潜伏期、收缩波个数、起始波压力值;采用免疫组织化学法检测结肠M_3受体的表达。结果与针前相比,针后合谷组及足三里组大鼠的大便评分显著降低(P0.01)。与空白对照组相比,模型对照组大鼠的大便评分显著增高(P0.01),潜伏期明显缩短(P0.01),收缩波个数明显增多(P0.01),起始波压力值明显降低(P0.01),结肠内M_3受体免疫反应物阳性表达水平明显增强(P0.01);合谷组结肠内M_3受体免疫反应物阳性表达水平增强(P0.05)。与模型对照组相比,合谷组和足三里组大鼠针后的大便评分均显著降低(P0.01),潜伏期均明显延长(P0.01),合谷组和足三里组收缩波个数明显减少(P0.01,P0.05),起始波压力值均明显增高(P0.01),结肠内M_3受体免疫反应物阳性表达水平明显下降(P0.01)。与合谷组相比,足三里组大鼠的大便评分降低(P0.05),起始波压力值显著降低(P0.01),结肠内M_3受体免疫反应物阳性表达水平下降(P0.05)。结论电针"合谷""足三里"穴均可抑制IBS模型大鼠肠道收缩,改善肠道敏感性,缓解IBS症状。但"合谷"穴缓解腹痛效果更佳,而"足三里"穴减轻腹泻作用更强。说明电针不同穴性及不同神经节段支配的穴位对IBS疗效具有经穴效应特异性。

Comparing the colonic motility and expression of M3 muscarinic receptor in IBS rats by stimulating LI 4 and ST 36 with electroacupuncture

Objective To observe and compare the effects of LI 4 and ST 36 electroacupuncture on co-lonic motility and positive expression of M3 receptor in colon of irritable bowel syndrome ( IBS ) model rats, and to explore the mechanism behind those differences. Methods 40 neonatal Wistar rats were randomly divided into blank control group, model group, LI 4 group, and ST 36 group. IBS rat model was built by using neonatal maternal separation and acetic acid enema, and colorectal distension ( CRD) stimulation in rats except the blank control group. At 9 weeks rats in LI 4 group and ST 36 group were given electroacupuncture( EA ) intervention once every other day for 5 times. Blank group and model group didn' t receive acupuncture intervention. After the treatment, Bristol Stool Scale was applied to i-dentify the feces types of the IBS rats before and after electroacupuncture invention;Abdominal withdraw-al reflex ( AWR) was evaluated to asess the intestinal sensitivities and smooth muscle contraction intensi-ty;and latency, contraction wave and pressure value of initial wave were observed;The expression of M3 receptor was measured using immunohistochemistry. Results Bristol scores of LI 4 group and ST 36 group significantly decreased (P<0. 01). Compared with blank group, the stool score of model group was significantly increased ( P<0 . 01 );the latency was shortened ( P<0 . 01 ); the number of contrac-tion waves was significantly increased (P<0. 01);the immunohistochemical expression of M3 receptor in the colon was significantly increased (P<0. 01). The immunohistochemical expression of M3 receptor in the colon in LI 4 group was increased (P<0. 01). Compared with model group, after electroacupuncture stimulation, the stool score of LI 4 group and ST 36 group was significantly decreased (P<0. 01); the latency was significantly prolonged ( P <0 . 01 ); the number of contraction wave was significantly de-creased in LI 4 group (P<0. 01) and ST 36 group (P<0. 05);immunohistochemical expression of M3 receptor in the colon was significantly decreased (P<0. 01). Compared with the LI 4 group, the stool score in ST 36 group was decreased ( P<0 . 05 );the pressure value of initial wave significantly decreased (P <0. 01); the immunohistochemical expression of M3 receptor in the colon was decreased ( P <0. 05 ) . Conclusion Stimulating LI 4 or ST 36 with electroacupuncturing could both inhibit gastrointesti-nal tract contraction, reduce intestinal sensitivity and relieve IBS symptoms in rats. LI 4 appears to be more effective than ST 36 in relieving abdominal pain, while ST 36 is better than LI 4 to stop diarrhea. Stimulating different acupoints or acupoints on different nerve segments with electro-acupuncture have specific effects on IBS rats.