黄连素与2型糖尿病大鼠胰岛素抵抗及胰岛素样生长因子-1的关系研究

RELATIONSHIP BETWEEN INSULIN RESISTANCE AND INSULIN-LIKE GROWTH FACTOR-1 IN RAT MODELS OF TYPET 2 DIABETES INTERVENED BY BERBERINE

目的:探讨黄连素对2型糖尿病(T2DM)大鼠空腹血糖(FBG)、空腹胰岛素(FINS)、胰岛素抵抗指数(HOMA-IR)及胰岛素生长因子-1(IGF-1)表达的影响。方法:SD雄性大鼠40只,随机取6只作为正常对照组,34只用链脲佐菌素(STZ)诱导T2DM大鼠模型,造模成功后随机分为T2DM模型组及T2DM治疗组。正常对照组始终予普通饲料喂养,T2DM模型组及T2DM治疗组予高糖高脂饲料喂养2周后予普通饲料喂养。T2DM治疗组予黄连素180mg/(kg·d)灌胃,正常对照组及T2DM模型组给予生理盐水灌胃,共6周。第6周末处死各组大鼠,留取血清标本测定FBG、FINS水平,计算HOMA-IR;留取各组大鼠胰腺组织,应用免疫组织化学法检测胰岛中IGF-1的表达,并使用Image pro plus 6.0软件计算IGF-1阳性表达的累计光密度值(IOD值)。结果:T2DM模型组及T2DM治疗组FBG、FINS、HOMA-IR均高于正常对照组(P<0.01),T2DM治疗组FBG、FINS、HOMA-IR均较T2DM模型组改善(P<0.05或P<0.01)。T2DM治疗组及T2DM模型组IGF-1表达较正常对照组减少(P<0.05)。T2DM治疗组中IGF-1值较T2DM模型组有所下降,但差异无统计学意义(P>0.05)。结论:黄连素能改善T2DM大鼠的胰岛素抵抗,IGF-1可能与黄连素改善T2DM大鼠的胰岛素抵抗无关。

Objective:Insulin-like growth factor-1(IGF-1)plays an important role in the occurrence and development of diabetes.Berberine has been shown to improve glucose metabolism and insulin resistance. The present study aimed to evaluate the anti-diabetic efficacy of berberine and its effective mechanism. Methods:Forty healthy adult male SD rats were randomly divided into normal control group(n=6,fed a standard diet)and experimental group(n=34,intraperitoneal injection of streptozotocin).The rats with fasting blood glucose(FBG)greater than 13.8mmol/L in experimental group were randomly divided into diabetes mellitus group and berberine group,fed high sugar high fat diet for two weeks,and then continued on a standard diet,and the berberine group was given berberine(180mg/kg per day),the normal control and diabetes mellitus groups were given physiological saline per day for 6weeks.At the end of 6th week, the rats were executed,and the levels of FBG,serum insulin,homeostasis model assessment of insulin resistance(HOMA-IR),expression of IGF-1in pancreas isle of each group were detected.The expression of IGF-1 in pancreas islet was examined by immunohistochemistry.The Image pro plus 6.0 software was applied to calculate the integrated optical density(IOD)of positive expression.Results:As compared with the normal control group,the levels of FBG,fasting serum lisulin(FINS)and HOMA-IR in the diabetes mellitus and berberine groups were significantly increased(P <0.05).After 6-week treatment with berberine,the levels of FBG,FINS and HOMA-IR and the IOD of IGF-1in pancreas islet were decreased,but there was not statistical significance between the berberine and diabetes mellitus groups(P >0.05).Conclusion:Berberine can improve the insulin resistance in type 2 diabetic rats which may not be associated with IGF-1.