去肝脏胆碱能神经与大鼠肝细胞胰岛素信号转导关系的研究

Relationship between isolated hepatic cholinergic denervation and insulin signal transduction in rat hepatocytes

目的 通过研究去肝脏胆碱能神经 (IHCD)大鼠肝细胞胰岛素信号转导过程中信号蛋白表达的改变 ,探讨IHCD对胰岛素信号转导的影响机制。方法 选用健康Wistar大鼠 30只 ,随机分为手术组、术后给药组和假手术组 ,每组 10只。手术组建立IHCD大鼠模型 ,术后给药组每日每只动物予罗格列酮 0 0 8mg灌胃一次 ,假手术对照。 4周后处死实验大鼠 ,留取肝组织标本 ,用Westernblot及免疫组织化学方法观察手术组大鼠胰岛素受体 (IR)、胰岛素受体底物 1(IRS 1)、葡萄糖载体蛋白 2 (Glut2 )等胰岛素信号蛋白及效应蛋白表达的改变 ,以及药物处理对这些蛋白表达的影响。结果 Westernblot显示手术组大鼠肝组织内IR、IRS 1、Glut2蛋白表达较假手术组明显降低 (P <0 0 5 ) ;术后给药组使用罗格列酮 4周后 ,IR、IRS 1、Glut2蛋白表达较手术组有不同程度的升高 (P >0 0 5 ) ,免疫组化的检查结果基本与之一致。结论 IHCD导致胰岛素信号转导通路中IR、IRS 1、Glut2等蛋白的表达降低 ,从而影响葡萄糖代谢过程 ,罗格列酮可增加它们的表达 。

Objective To observe the changes of signal protein expression in insulin signal transduction in rat hepatocytes after isolated hepatic cholinergic denervation (IHCD) to discuss the mechanism of influence of IHCD on insulin signal transduction. Methods A total of 30 healthy Wistar rats were randomized into the operated group, postoperative medication group and sham-operated group, with 10 rats in each. The IHCD rat model was established according to the method that we previously reported. Rosiglitazone was orally administered each rat in the postoperative medication group at a dose of 0.08 mg/day. Four weeks later, all the rats were sacrificed to harvest liver specimens to observe expression of insulin signal proteins and effective proteins such as insulin receptor (IR), insulin receptor substrate-1 (IRS-1) and glucose transporter 2 (Glut2) in IHCD rats and the therapeutic effects of rosiglitazone with Western Blot and immunohistochemistry. Results Western blot showed that protein expression of IR, IRS-1 and Glut2 diminished in livers of IHCD rats (P<0.05). Rats administered with rosiglitazone for 4 weeks after IHCD had higher expression of these 3 signal proteins (P>0.05). These results agreed with those of immunohistochemical examination. Conclusions IHCD causes the expression of insulin signal transducting proteins such as IR, IRS-1 and Glut2 to decrease, so as to influence the glucose metabolism course. Rosiglitazone can increase their expression. The integrity of hepatic cholinergic nerve system is necessary for regulating and maintaining the balance of glucose metabolism.