Apoptosis and connexin 43 expression in colonic interstitial cells of Cajal in diabetic rats with colonic dysmotility

Abstract

Objective To investigate the apoptosis and expression of connexin 43 (Cx43) of colonic interstitial cells of Cajal (ICC) in diabetic rats with colonic dysmotility, and explore their value in the development of colonic dysmotility. Methods Thirty-six male Sprague-Dawley(SD) rats were divided into 4 groups which included normal 6 weeks group, normal 10 weeks group, diabetes mellitus (DM) 6 weeks group and DM 10 weeks group (n=9) by random digital table method according to weight and fasting blood glucose (FBG). DM was induced by streptozotocin. Weight, FBG and gastrointestinal transit rate were detected. HE staining was used to examined ICC. TUNEL was used to detect apoptosis index (AI) of ICC. Immunohistochemistry was used to detect the protein expressions of c-Kit and Cx43 of ICC. Results (1)Compared with normal group, level of FBG was higher, while weight, gastrointestinal transit rate, protein expressions of c-Kit and Cx43 of ICC were lower in DM group(F=76.68, 1 397.24, 18.87, 137.65, 87.73, all P 0.05). Conclusions Decrease of ICC and less expression of Cx43 maybe one of the mechanisms of diabetic colonic dysmotility, and the changes above become more significant with the development of disease. Decrease of ICC may be not associated with the apoptosis of ICC. Key words: Interstitial cells of Cajal; Apoptosis; Connexin 43; Diabetes mellitus