梓醇对糖尿病大鼠胰岛细胞Insulin表达的影响

The Influcece of Catalpol on the Expression of Insulin in Islet Cells of Diabetic Rats

目的观察梓醇对糖尿病大鼠胰岛细胞Insulin表达的影响。方法选取雄性Wistar大鼠,8周龄,根据随机数字表法分为正常组(10只)与实验组(90只)。实验组饲养8周高糖高脂饮食后经腹腔注射链脲佐菌素15 mg/kg,以空腹血糖≥16.7 mmol/L作为2型糖尿病成模标准,将符合2型糖尿病成模标准的60只大鼠随机分为模型组、二甲双胍组、梓醇低剂量组、梓醇中剂量组、梓醇高剂量组。正常组和模型组灌胃蒸馏水5mL/(kg·d);二甲双胍组灌胃二甲双胍90 mg/(kg·d);梓醇低、中、高剂量组分别灌胃梓醇2.5mg/(kg·d)、5mg/(kg·d)、10mg/(kg·d)。分别干预12周后,经免疫组化检测胰岛细胞Insulin的表达水平,Western Blot检测腺苷酸活化蛋白激酶-α1(AMPK-α1)蛋白表达。结果免疫组化染色显示,各组大鼠胰岛细胞Insulin均有表达,与模型组相比,二甲双胍组、梓醇各剂量组大鼠胰岛细胞Insulin表达增多,其中梓醇高剂量组、梓醇低剂量组Insulin表达与二甲双胍组比较差异有统计学意义(P<0.01)。Western Blot检测结果显示,与模型组比较,二甲双胍组、梓醇低剂量组、梓醇中剂量组、梓醇高剂量组胰岛细胞AMPK-α1蛋白表达相对增多(P<0.01),其中梓醇高剂量组AMPK-α1蛋白表达较二甲双胍组、梓醇低剂量组、梓醇中剂量组表达增多,差异有统计学意义(P<0.01)。结论梓醇可促进糖尿病大鼠Insulin分泌,其机制可能是通过上调AMPK-α1蛋白表达发挥作用。

Objective To study the effect of Catalpol on the expression of insulin in islet cells of diabetic rats.Methods Eight weekold male wistar rats were randomly divided into the blank group （ n =10） and the experimental group （ n =90）.The rats in experimen -tal group were fed with high fat and high sugar diet for 8 weeks,after intraperitoneal injection of streptozotocin （STZ,15 mg/kg）,withfasting blood glucose≥16.7 mmol/L as type 2 diabetes model standard.Sixty diabetic rats were randomly divided into model group,metformin group,catalpol low- ,middle -and high- dose group.The rats in blank group and model group were fed with distilled water 5mg/（kg·d）.The rats in metformin group was given metformin 90 mg/（kg·d）.The rats in catalpol low -,middle -and- high -dose groupwere fed catalpol 2.5 mg/（kg·d）,5 mg/（kg·d）,10 mg/（kg·d）.After 12 weeks,the expression levels of insulin on islet cells were meas -ured by immunohistochemistry.AMP activated protein kinase （AMPK） -α1 protein expression was detected by western blot.Results Immunohistochemical staining showed that insulin was expressed on islet cells in all groups.Compared with the model group,the ex -pression of insulin on islet cells in metformin group and catalpol low ,middle and high dose group were relatively higher.There wasdifference in the expression of insulin between metformin group and catalpol middle dose group or high dose group （ P 〈0.05）.Western blot results showed that compared with the model group,the expression of AMPK- α1 protein in the islet cells were relativelyincreased in metformin group,catalpol low- ,middl-e and high- dose group （P 〈0.05）.The expression of AMPK- α1 protein in catal-pol high dose group was higher than that in in metformin group,catalpol low ,middle dose group （P 〈0.05）.Conclusion Catalpolcan protect the islet cells and promote the secretion of insulin,which may be the mechanism through up regulating AMPK -α1 proteinexpression in diabetic rats.