ABSTRACT
Objective To explore the anti-apoptotic mechanism of Roux-en-Y gastric bypass (RYGB) through exam?ine the postoperative change of adiponectin levels and expressions of pancreatic islets relative apoptotic protein. Methods Sixty SD rats were randomly allocated to RYGB group (n=20), type 2 diabetes mellitus group (T2DM, n=20) and normal con?trol group (NC, n=20). Rats in the NC group were fed with normal diet. In order to make type 2 diabetic rat models, the rats in the T2DM and RYGB groups were fed with high fat diet (22.19 kJ/g) combined with administration of intraperitoneal strep?tozotocin injection (STZ, 30 mg/kg) on the 13th day of high fat diet. RYGB operation were performed in RYGB group and sham-operation were performed in the T2DM and NC groups when diabetic model was contructed. Rats were weight preoper?atively and at the 7th, 14th, 21st days after operations. Fasting plasma glucose and adiponectin (ELISA) were measured preoper?atively and at 21st day postoperatively. Protein expressions of Bcl-2,Caspase 8 and Caspase 9 in pancreatic islets were ex?amined by immunohistochemistry at the 21st day postoperatively. Results Body weights do not vary significantly among three groups preoperatively. Compared to rats in the NC group, fast plasma glucose level was higher but adiponectin was low?er in rats in RYGB and T2DM groups. Body weights of rats in RYGB group decreased significantly compared to those of rats in NC and T2DM groups postoperatively. Compared to rats in T2DM group, fasting glucose level was lower while adiponectin concentrations was higher in rats in RYGB group but no differences of these parameters were seen in rats in NC group at the 21st day postoperatively. Expression of Bcl-2 in RYGB group was significantly elevated while expressions of Caspase 8 and Caspase 9 were significantly decreased compared to those in T2DM group postoperatively. Conclusion Adiponectin levelswas elevated;expressions of Bcl-2 was increased;expressions of Caspase 8, Caspase 9 were decreased upon RYGB opera?tion in T2DM model. RYGB might reduce pancreatic islets apoptosis through mitochondrial pathway.