丝胶对糖尿病大鼠下丘脑神经肽Y和瘦素表达的调节作用

Regulations of sericin on the expression of neuropeptide Y and leptin in hypothalamus of diabetic rats

目的:探讨丝胶对糖尿病大鼠下丘脑神经肽Y(NPY)和瘦素表达的调节作用.方法:大鼠随机分为正常对照组、模型组、丝胶组和二甲双胍组.除正常对照组外,其他3组均建立链脲佐菌素致糖尿病模型,以血糖(BG)≥16.7 mmol/L作为成模标准;丝胶组和二甲双胍组分别在成模后予以丝胶和二甲双胍灌胃35 d.采用葡萄糖氧化酶法检测各组大鼠血糖、免疫组织化学和RT-PCR检测各组大鼠下丘脑NPY、瘦素蛋白和mRNA水平.结果:丝胶组和二甲双胍组大鼠血糖、NPY和瘦素蛋白及mRNA表达均显著低于模型组,两组间比较无统计学意义.结论:丝胶可通过下调下丘脑NPY和瘦素的高表达以减少糖尿病时下丘脑的损伤;并且丝胶对下丘脑损伤的保护作用与二甲双胍相当.

Objective:To investigate the regulating effects of sericin on neuropeptide Y(NPY) and leptin expression in hypothalamus of diabetic rats.Methods:The rats were randomly divided into 4 groups:normal control group,model group,sericin group and metformin group.Rats in the model,sericin and metformin group were continuously injected streptozotocin intraperitoneally to make diabetes,confirmed by the concentration of blood glucose(BG)≥16.7 mmol/L.After diabetes model was established successfully,the rats in the sericin group and the metformin group were lavaged with sericin and metformin respectively for 35 days.The BG concentration of rats in each group was detected by glucose oxidase method respectively.Immunohistochemical staining and RT-PCR were used to investigate the protein and mRNA expression of NPY and leptin in the hypothalamus.Results:In contrast with diabetic rats,the BG,the protein and mRNA of NPY and leptin in the sericin and metformin group rats decreased markablely but no significant difference was found between the two groups.Conclusion:Sericin can reduce the hypothalamus injury of diabetic rats through down regulating the high expression of NPY and leptin.Moreover,the protective effects of sericin on injured hypothalamus of diabetic rats are similar to metformin.