Abstract:

Objective To explore the mechanism of continuous glycometabolism improvement by Roux-en-Y gastric bypass (RYGB) surgery in GK rats. Methods Twenty-four male GK rats were randomly divided into RYGB surgery group, sham operation diet control group and blank control group, with 8 rats in each group. Besides, 8 Wistar rats were served as normal control group. The body weight of rats was measured regularly. Oral glucose tolerance tests were performed 1, 3 and 6 months after surgery in all groups. Six months after surgery, intravenous glucose tolerance test was performed, and plasma insulin was detected in each group. Plasma free fatty acids and triglyceride were determined after the rats were sacrificed 6 months after surgery, and the expression of insulin receptor in the liver was detected by Western blotting. Results The body weight of rats in RYGB surgery group was well controlled after surgery, and the body weight of rats in RYGB surgery group was significantly lower than that in the other groups 6 months after surgery (P<0.05). Oral glucose tolerance tests 1, 3 and 6 months after surgery and intravenous glucose tolerance test 6 months after surgery demonstrated that all the parameters in RYGB surgery group were superior to those in sham operation diet control group and blank control group. Six months after surgery, plasma free fatty acids and triglyceride in RYGB surgery group were significantly lower than those in sham operation diet control group and blank control group (P<0.05), while the expression of insulin receptor in the liver in RYGB surgery group was significantly higher than that in sham operation diet control group and blank control group (P<0.05). Conclusion RYGB surgery plays a role in the continuous glycometabolism improvement in GK rats, which may be associated with the relief of insulin resistance and restoration of islet function promoted by decreased plasma free fatty acids and triglyceride.

Key words: type 2 diabetes mellitus, Roux-en-Y gastric bypass surgery, glycometabolism