黄芪预防肿瘤坏死因子-α所致胰岛素抵抗

Preventive Effect of Radix Astragali on Insulin Resistance Caused by Tumor Necrosis Factor α

目的：探讨黄芪对大鼠注射肿瘤坏死因子α（ＴＮＦα）后发生胰岛素抵抗（ＩＲ）的预防作用。方法：取正常大鼠分别给予黄芪煎剂和等量蒸馏水预先灌胃１周，尾静脉注射小剂量ＴＮＦα４ｈ后，以葡萄糖－胰岛素耐量试验（ＧＩｎｓＴＴ）检测其胰岛素敏感性等一些指标的变化。结果：外源性ＴＮＦα可致正常大鼠出现高胰岛素血症，胰岛素敏感性Ｋ值下降，并有血浆胰高血糖素、促肾上腺皮质激素和血脂水平的升高，肝脏和红色股四头肌糖原含量减少，肝脏中甘油三酯（ＴＧ）含量升高。黄芪除对血脂和肝脏中ＴＧ无明显改善外，对其它指标均有不同程度的改善作用。结论：黄芪对外源性ＴＮＦα所致ＩＲ有明显的预防作用，可能与降低血中拮抗激素水平和增加组织糖原合成有关。

Objective: To investigate the preventive effect of Radix Astragali (RA) on insulin resistance caused by tumor necrosis factor α (TNF α). Methods: Normal rats were pretreated with RA or distilled water by intragastric infusion for one week. Glucose insulin tolerance test was conducted in the rats 4 h after low dose TNF α injection by caudal vein to estimate the change in insulin sensitivity. Meanwhile, the plasma glucagon, ACTH, blood lipid, and glycogen, triglyceride in tissue were also observed. Results: Exogenous TNF α could induce hyperinsulinemia in normal rats. K value in glucose insulin tolerance test decreased, serum ACTH, glucagon, blood lipid increased, glycogen content in liver and red quadriceps muscles decreased, the liver triglyceride level increased in the TNF α treated rats. RA could improve all the above mentioned changes significantly except the blood lipid and triglyceride depots in liver. Conclusion: RA has obvious preventive effect on in sulin resistance caused by TNF α, it may be due to its action in decreasing insulin antagonistic hormones and increasing glycogen synthesis in tissue.