目的：通过研究脂联素及胰岛凋亡相关蛋白的变化，探讨Roux-en-Y胃旁路术（RYGB ）减少胰岛细胞凋亡的机制。方法60只SD大鼠随机分为RYGB组、2型糖尿病（T2DM）组和正常对照（NC）组，每组20只。NC组喂食正常饲料；为了建立T2DM动物模型，T2DM组和RYGB组大鼠喂食高脂饮食（22.19 kJ/g）3周，并于第13天经腹腔注入链脲佐菌素（STZ，30 mg/kg）。造模成功后，RYGB组大鼠行RYGB手术、T2DM及NC组行假手术。术前、术后7、14及21 d测定体质量；术前及术后21 d测定空腹血糖，ELISA法测定血浆脂联素水平；术后21 d免疫组化SABC法检测胰岛Bcl-2、Caspase 8、Caspase 9表达。结果术前3组体质量差异无统计学意义；RYGB和T2DM组血糖明显高于NC组，脂联素水平明显低于NC组（P<0.05）。与T2DM及NC组相比，术后RYGB组体质量明显降低。与T2DM组相比RYGB组术后21 d时血糖明显降低、脂联素水平明显升高（P<0.05），RYGB组与NC组相比差异无统计学意义。与T2DM组相比RYGB组术后胰岛Bcl-2表达明显升高，Caspase 8、Caspase 9表达明显降低（P<0.05）。结论 RYGB术后可以使脂联素水平升高、Bcl-2表达增加，Caspase 8、Caspase9表达减少；RYGB术可能通过线粒体通路减少胰岛细胞凋亡。%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.
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