丹蛭降糖胶囊对糖尿病GK大鼠肝脏胰岛素受体底物的影响

Effects of Danzhi Jiangtang Capsule on insulin receptor substrates in liver of diabetic GK rats

目的:观察丹蛭降糖胶囊(DJC)对糖尿病大鼠肝脏胰岛素抵抗的干预效果,并探讨其缓解肝脏胰岛素受体底物减少的机制。方法:选取12周龄符合糖尿病模型的SPF级雄性GK大鼠40只纳入实验,随机分为模型组,DJC低、高剂量组,吡格列酮组,另设10只同周龄正常Wistar大鼠作为正常组。DJC低、高剂量组和吡格列酮组分别予以0.54、1.08g·kg^-1·d^-1 DJC和吡格列酮10mg·kg^-1·d^-1灌胃,模型组及正常组给予等量0.9%氯化钠溶液。连续给药6周后,测定各组大鼠的空腹血糖(FBG)、血清胰岛素(FINS),计算胰岛素抵抗指数(HOMA-IR),检测肝脏病理染色和胰岛素受体底物IRS1、IRS2的免疫组化结果,Western blot检测mTOR通路蛋白p-mTOR、p-S6K1,AMPK通路蛋白LKB1、p-AMPK和IRS1、IRS2的表达。结果:与正常组比较,模型组大鼠具有血糖升高,胰岛素抵抗特征,HE染色显示有显著的肝脏细胞脂肪变性;与模型组比较,DJC低、高剂量组的FBG、FINS和HOMA-IR均显著改善(P<0.05),肝脏脂肪病变和炎症浸润减轻;p-mTOR、p-S6K1表达下降(P<0.01);IRS1、IRS2,LKB1、p-AMPK表达增高(P<0.01);其中DJC高剂量组和吡格列酮组的IRS1、IRS2的表达高于DJC低剂量组(P<0.05)。结论:DJC可以增加糖尿病GK大鼠肝脏胰岛素受体底物的表达,减轻肝脏脂肪病变,相关机制可能与抑制mTOR信号通路并增强AMPK信号通路有关。

Objective: To observe the therapeutic effect of Danzhi Jiangtang Capsule(DJC) on hepatic insulin resistance in type 2 diabetic rats and explore the mechanism of relieving the decrease of insulin receptor substrate in liver. Methods: Forty male SPF grade GK rats were randomly divided into four groups: model group, low dose group, high dose group, pioglitazone group, and another 10 Wistar rats of the same week age as normal control group. 0.54 g·kg^-1·d^-1 and 1.08 g·kg-1·d-1 Danzhi Jiangtang Capsules were given to the low and high dose groups of traditional Chinese medicine, 10 mg·kg^-1·d^-1 of pioglitazone hydrochloride tablets was given to the western medicine group, and the model group and the normal control group were given the same amount of 0.9%NaCl solution. After 6 weeks of continuous administration, fasting blood glucose(FBG) and serum insulin(FINS), were measured to calculate insulin resistance index(HOMA-IR). The expression of two insulin receptor substrates(IRS-1, IRS-2) and p-mTOR, p-S6 K1, p-AMPK, LKB1 in liver tissue were detected by immunohisto-chemistry and pathological examination. Results: Compared with the model group, the rats in the model group had obvious elevated blood glucose, insulin resistance and significant steatosis of liver cells. Compared with the model group, the FBG, FINS and HOMA-IR in the high dose group were significantly improved(P<0.05), the fatty lesions and inflammatory infiltration of the liver were alleviated, the expression of p-mTOR, p-S6 K1 was decreased(P<0.01) and the expression of LKB1, p-AMPK was increased in the model group(P<0.01). The expression of IRS1, IRS2 in liver tissue was significantly higher than that in model group(P<0.01), especially in high dose DJC group and pioglitazone group(P<0.05). Conclusion: DJC can increase the expression of insulin receptor substrate in the liver of diabetic GK rats and alleviate the fatty lesions of the liver. The related mechanism may be related to the inhibition of mTOR signaling pathway and the enhancement of AMPK signaling pathway. Conclusion: Danzhi Jiangtang Capsule can reduce the absence of insulin receptor substrate in liver of diabetic GK rats. The mechanism of the treatment of insulin resistance may be related to the inhibition of mTOR signal pathway and the enhancement of AMPK signal pathway.