胃转流术对GK大鼠胰岛纤维化的影响

摘要

目的 探讨胃转流术对GK大鼠胰岛纤维化的影响.方法 雄性GK大鼠40只,高脂饲料喂养1 w模后,随机分为手术组和假手术组各20只.手术组行胃转流术,假手术组行胃窦十二指肠离断原位吻合术,分别于术前、术后1、2、4 w,测定各组空腹血糖、口服糖耐量试验(OGTT)后2 h血糖;术后4 w,分别采用免疫组化及免疫荧光双染检测各组胰岛内胰岛素、纤维连接蛋白(FN)、胶原蛋白 - Ⅲ(CO - Ⅲ)和巨噬细胞的表达水平.采用Image - Pro plus 6.0图像分析软件测定胰岛素含量及FN、CO - Ⅲ和巨噬细胞表达情况.结果 与术前相比,手术组术后2、4 w的空腹和术后4 w的OGTT 2 h血糖显著降低(P＜0.05);与假手术组相比,手术组术后2、4 w空腹和术后4 w的OGTT 2 h血糖显著降低(P＜0.01);与假手术组比较,手术组术后4 w单位胰岛面积中FN、CO - Ⅲ、巨噬细胞的累计光密度值(IOD)明显降低(P＜0.05),胰岛素的IOD明显增高(P＜0.05);术后4 w,手术组较假手术组的胰岛形态规则.结论 胃转流术后,GK大鼠胰岛的纤维化有所减轻,是其治疗2型糖尿病的可能机制之一.%Objective To discuss the influence of gastric bypass surgery on the fibrosis of pancreatic islet in GK rats. Methods Forty male GK rats were fed with high - fat diet for 1 w, and then randomly divided into operation group and sham operation group with 20 ones in each group. The operation group received the gastric bypass surgery, and the sham operation group received transection and reanastomosis of the gastrointestinal tract. The fasting blood glucose and the glucose 2 h after the oral glucose tolerance test (OGTT )in both groups were detected before the operation and 1,2, and 4 w after the operation. The expression levels of insulin, fibronectin( FN ), collagen - Ⅲ and macrophage in pancreatic islet of both groups were detected by immunohistochemistry and immunofluorescence double staining 4 w after the operation. The insulin contents and the expression of FN,CO - Ⅲ and macrophages were determined by Image - Pro plus 6. 0 image analysis software. Results In the operation group,fasting blood glucose 2 and 4 w after the operation and glucose 2 h after the OGTT 4 w after the operation decreased significantly compared with those before the operation ( P < 0. 05 ). Compared with fasting blood glucose 2 and 4 w after the operation and glucose 2 h after the OGTT 4 w after the operation in the sham operation group,those in the operation group decreased more significantly( P <0. 01 ). Compared with the sham operation group,the IOD of FN,CO - Ⅲ and macrophages in the same area of pancreatic islet in the operation group decreased significantly 4 w after the operation( P <0. 05 ),and the IOD of insulin increased significantly( P <0. 05 ). The morphous of pancreatic islet in the operation group was more regular than that in the sham operation group 4 w after the operation. Conclusion The fibrosis of pancreatic islet in GK rats decreases after the gastric bypass surgery, which is a possible mechanism for the treatment of type 2 diabetes mellitus.