3T3-L1脂肪细胞胰岛素抵抗模型建立的3种方法对葡萄糖转运时效关系的影响

目的:对比3种不同方法(地塞米松、游离脂肪酸、高糖高胰岛素)诱导的胰岛素抵抗3T3-L1脂肪细胞的葡萄糖转运时效关系及对葡萄糖转运子4(Glut4)蛋白表达的影响.方法:采用3种不同方法诱导3T3-L1脂肪细胞产生胰岛素抵抗,分别检测各组细胞12,24,36,48及60h时的葡萄糖转运率及各组细胞60 h后Glut4蛋白的表达.结果:在24 h内,造模组细胞的葡萄糖转运率与正常对照组相比均明显降低(P＜0.01);在24 h以后,游离脂肪酸组葡萄糖转运率与正常对照组相比无明显统计学差异(P＞0.05),地塞米松组葡萄糖转运率相比正常对照组明显降低(P＜0.05),而高糖高胰岛素组葡萄糖转运率较地塞米松组明显降低(P＜0.01);地塞米松组及游离脂肪酸组的Glut4蛋白表达水平较正常对照组明显降低(P＜0.01);相对于地塞米松组及游离脂肪酸组,高糖高胰岛素组的Glut4蛋白表达水平明显降低(P＜0.01).结论:高糖高胰岛素能够诱导3T3-L1脂肪细胞产生更强的胰岛素抵抗,这种抗性的产生可能是因为抑制了Glut4蛋白的表达获得的.

Time-Effect Study of Glucose Transportation in Insulin Resistance Models of 3T3-L1 Adipocytes by Three Different Methods

Objective: To observe the glucose transportation and Glut4 expression in the induction of insulin resistance in 3T3-L1 adipocytes by three methods(dexamethasone,free fatty acids,and high glucose/hyperinsulinism).Methods: Insulin resistance was induced in three different model groups of 3T3-L1 adipocytes according to the three different methods.The glucose transportation rate was detected by the uptake of 2-deoxy——D-glucose in each group after 12,24,36,48 and 60 hours.The Glut4 expression was assayed by means of Western blot after 60 hours.Results: Within 24 hours,as compared with normal control group,the glucose transportation in each model group decreased significantly(P<0.01).After 24 hours,as compared with that in normal control group,the glucose transportation rate in free fatty acid group showed no difference(P>0.05),but decreased obviously in dexamethasone group(P<0.05),while the rate in high glucose and hyperinsulinism group decreased significantly even than that in dexamethasone group(P<0.01).The Glut4 expression in dexamethasone group and free fatty acids group both decreased significantly as compared with normal control group(P<0.01).And compared with that respectively in dexamethasone group and free fatty acids group,the Glut4 expression in high glucose and hyperinsulinism group decreased significantly(P<0.01).Conclusion: High glucose and hyperinsulinism can induce 3T3-L1 adipocytes to produce stronger insulin resistance,and the production of the resistance may be due to the inhibition of Glut4 expression.