An Experimental Study on Intestine Transmission Function in SD Rats With Slow Transit Constipation After Electro-acupuncture Treatment in BL32 Acupoints

Objective:This study aims to use loperamide by gavage in SD rats to establish the model of STC, and evaluate the degree of similarity between the model and clinical diseases. Furthermore, the effect of electro-acupuncture when stimulating BL32 acupoints in SD rats with slow transit constipation were observed to determine changes in intestinal transmission function. Methods:Thirty SD rats were selected and divided randomly into three groups. Rats in the model group were given 2 mg/kg/d of loperamide tablets by gavage for 15 days. The morphology of the feces of rats was observed, and the dry weight of the feces and the time of first black feces movement with black ink by gavage after molding were measured. After 20 days of electro-acupuncture treatment at the BL32 acupoint, the time of first black feces movement, the ratio of black ink length of the entire length of the intestine, and contraction amplitude and frequency of contraction were measured. Results: The time of black feces movement in the two model groups was significantly prolonged (P<0.05).Furthermore, fecal grains, dry weight and moisture content were significantly reduced (P<0.05). On the 10thand 20thday of treatment, the time of black feces movementin the treatment group significantly decreased (P<0.05). The ratio of black ink length of the entire length of the intestine in the electro-acupuncture group was significantly higher than that in the model group (P<0.05). Moreover, contraction amplitude was significantly higher than in the model control group (P<0.05). Conclusion: Through loperamide gavage, the model of slow transit constipation in SD rats was successfully established in a relatively short period of time. Electro-acupuncture treatment had a rapid onset of action, and its mechanism might have been caused through strengthening the ability of intestinal smooth muscle contraction, and are independent with increased smooth muscle contraction frequency.