Insulin-like growth factor-1 inhibits colonic smooth muscle cellapoptosis in diabetic rats with colonic dysmotility

摘要

Cellular apoptosis and colonic dysmotility are involved in diabetes mellitus (DM) complications. Insulin-likegrowth factor-1 (IGF-1) is known to affect apoptosis and proliferation. Here, we demonstrated that the treatmentof 1500 ng/kg IGF-1 partly recovers the decrease of the muscle thickness, body weight and gastrointestinal transitrate in DM rats. The gastrointestinal transit rate is positively correlated with the IGF-I level, but negativelycorrelated with the level of colonic cellular apoptosis. The DM-induced colonic apoptosis is also attenuated bythe IGF-1 stimulation. Moreover, IGF-1 inhibits the apoptosis of the isolated colonic SMCs in vitro via theactivation of PI3K/Akt and ERK1/2 signaling pathways. Taken together, our data indicated that IGF-1 inhibitsthe DM-induced colonic SMC apoptosis and might be involved in the alleviation of colonic dysmotility in diabeticrats.