OBJECTIVE

To observe the effect of electroacupuncture (EA) intervention on constipation-predominant irritable bowel syndrome (C-IBS) and colonic calcitonin gene-related peptide (CGRP) and substance P (SP) expression levels in IBS rats, so as to reveal its mechanism underlying improvement of lBS.

METHODS

A total of 32 male Wistar rats were equally ran-domized into normal control, model, EA-Shangjuxu (ST 37) and EA-Dachangshu (BL 25) groups. The C-IBS model was established according to Peng's methods (2004). EA (2 Hz/100 Hz, 0.1-0.2 mA) was applied to bilateral ST 37 and BL 25 for 30 min, once daily for 7 days. The stool properties (hardness or softness, water content, etc.) were typed (1-7 points) and the fecal water content was calculated by wet weight minus dry weight. The relative expression levels of CGRP and SP proteins in the colon tissues were detected by Western blot.

RESULTS

Compared to the control group, the stool property score and stool water content were significantly lower in the model group (P < 0.01). After EA intervention, both stool property scores and stool water contents were obviously higher in the EA-ST 37 and EA-BL 25 groups than in the model group (P < 0.05, P < 0.01). The expression levels of colonic CGRP and SP proteins were significantly higher in the model group than in the control group, and obviously down-regulated in the two EA intervention groups (P < 0.01). No significant differences were found between the EA-ST 37 and EA-BL 25 groups in the stool property score and stool water content, and colonic CGRP and SP protein expression levels (P > 0.05).

CONCLUSION

EA intervention can ameliorate the fecal property in C-IBS rats, which may be associated with its function in inhibi-ting the expression of colonic CGRP and SP proteins.