OBJECTIVETo explore the efficacy and the mechanism of Bisacodyl in treating slow transit constipation model rats.

METHODSA total of 30 healthy rats were enrolled. Twenty rats received intragastric diphenoxylate to develop slow transit constipation (STC) model, and 10 untreated rats were set as blank control. STC rats were subdivided into two groups: STC Bisacodyl group (fed with Bisacodyl) and STC control group (common feed). Body weight, number and dry weight of faeces, and intestinal transit time were compared among 3 groups. Interstitial cells of Cajal(ICC) and c-Kit protein expression were measured by immunohistochemical staining. Restults Compared to blank control rats, at 100-day of receiving intragastric diphenoxylate, above 20 rats presented the decrease of body weight and feces number, the increase of dry weight of faeces, and the delay of intestinal transit time, indicating the successful establishment of STC rat model. One month after feeding, compared to STC control group, STC Bisacodyl grap had an increased feces number[(36.6±6.8) pill/day vs. (26.8±6.0) pill/day], decreased dry weight of feces [(150.6±10.5) mg/pill vs. (171.6±16.3) mg/pill] and shortened intestinal transit time [(416.9±50.6) minutes vs. (495.3±66.8) minutes], and the differences were statistically significant(all P<0.05). Dissolution of ICC basement membrane, damage of connection between ICC and surrounding cells, and atrophy of ICC nucleus structure were found in STC control rats. ICC (8.20±1.92 per field] and c-Kit expression (12.68%±2.59% ) in STC control rats were significantly lower than those in blank control rats(36.00±6.25 per field and 71.50 %±8.27%) (P=0.000). Compared to STC control group, the connection between ICC and surrounding cells enhanced obviously, ICC (18.80±3.70 per field) and c-Kit expression (45.91%±6.80%) were significantly higher in STC Bisacodyl group (all P=0.000).

CONCLUSIONBisacodyl treatment can relieve STC symptoms, which may be associated with increased ICC number and c-Kit protein expression.