Effect of Electroacupuncture at "Neiguan" (PC 6) and "Tianshu" (ST 25) for Colonic Motility and D 2 Receptor in Irritable Bowel Syndrome Rats / 针刺研究

ABSTRACT

OBJECTIVE: To observe and compare the effects of electroacupuncture (EA) at "Tianshu" (ST 25) and "Neiguan" (PC 6) for colonic motility and the expression of colon dopamine D 2 in irritable bowel syndrome (IBS) rats, and to explore the specificity of different meridians and different acupoints. METHODS: Forty Wistar newborn rats were randomly divided into blank, model, Tianshu and Neiguan groups. Separation of mother and child and acetic acid coloclyster combined with colorectal distension were used to establish IBS model in the model, Tianshu and Neiguan groups. At the age of 9 weeks, EA at bilateral ST 25 and PC 6 were applied in the corresponding groups 5 times, once every other day. After the intervention, the Bristol fecal score, the latent period of abdominal retraction reflex and the number of contraction waves were recorded. The expression of dopamine D 2 receptor was detected by immunohistochemistry. RESULTS: Compared with the blank group, the Bristol fecal score of the model group was higher (P<0.01), the 1st contraction wave latent period was shorter (P<0.01), the number of contraction waves in 90 s increased (P<0.01), the immunoreactive expression of D 2 receptor in colon decreased (P<0.01). Compared with the model group, the Bristol fecal scores of the Tianshu and Neiguan groups decreased (P<0.01), the 1st contraction wave latent periods were longer (P<0.01), the numbers of contraction waves in 90 s decreased (P<0.01), the positive expressions of D 2 receptor in colon increased (P<0.01, P<0.05). Compared with the Tianshu group, the immunoreactive expression of D 2 receptor in the Neiguan group decreased (P<0.01). CONCLUSION: EA at ST 25 and PC 6 can improve the symptoms of colonic motility in IBS rats. The effect of EA at ST 25 is better, which indicates that different meridians and different acupoints play specific effects.