藻蓝蛋白对2型糖尿病大鼠胰腺组织iNOS表达的影响

目的研究藻蓝蛋白对糖尿病大鼠胰岛细胞功能的影响及其可能的机制。方法健康雄性Wistar大鼠32只,应用高脂高糖饲料喂养联合小剂量链脲佐菌素(STZ)腹腔注射方法建立2型糖尿病大鼠模型,藻蓝蛋白灌胃治疗,生化方法测定空腹血糖,组织病理学技术观察胰岛细胞的形态结构,免疫组化技术检测胰岛细胞诱导型一氧化氮合酶(iNOS)的表达。结果大鼠造模成功后,体重较正常组明显降低,空腹血糖明显升高,胰岛萎缩、结构模糊,细胞排列紊乱,胞浆肿胀、空泡变性等,胰岛细胞iNOS表达增强(P<0.05)。经藻蓝蛋白治疗后空腹血糖较模型组明显降低,有显著性差异(P<0.05)。经藻蓝蛋白和二甲双胍治疗后,大鼠胰岛细胞iNOS表达较糖尿病模型组均明显降低,胰岛细胞形态结构有所改善。结论藻蓝蛋白可抑制糖尿病胰岛大鼠胰岛细胞中iNOS表达,对胰岛细胞具有保护作用。

Objective To study the effect and mechanism ofphycocyanin on the function of islet cells of diabetic diseases in rats.Methods Type 2 diabetes mellitus models were induced by high fat diet and low dose intraperitoneal injection of streptozotocin （STZ） in 32 healthy male Wistar rats, and treated with phycocyanin. The free blood glucose （FBG） was determined by biochemical assay. The morphology and structures of islet cells were observed by histopathological technique. The expression of inducible nitric oxide synthase （iNOS） in islet cells was detected by immunohistochemical technique. Results In model group, the rat weight decreased and the free blood glucose （FBG） increased significantly than those in normal control group rats. The islet shrink, the islet cells arranged disorderly with plasma swelling and vacular degeneration, the expressions of iNOS increased significantly in islet cells of model group rats （P〈0.05）. After treatment with phycocyanin, the FBG significantly reduced （P〈0.05）. In phycocyanin and dimethylbiguanide group rats, the iNOS in islet cells expressed highly and the morphology and structure improved significantly than those in model group rats. Conclusion It is suggested that phycocyanin might protect the islet cells by inhibit the expression ofiNOS.