波动性高胰岛素对内皮细胞一氧化氮合酶信使核糖核酸的影响

Effect of Intermittent High Insulin on mRNA Transcription of eNOS of Vascular Endothelial Cell

目的:对比研究波动性高浓度胰岛素与恒定性高浓度胰岛素对体外培养的人脐静脉内皮细胞eNOS mRNA转录水平的影响,从而探究波动性高浓度胰岛素血症在糖尿病动脉粥样硬化形成中的致病机制。方法:采用体外培养的人脐静脉内皮细胞为对象,研究波动性高胰岛素对血管内皮细胞eNOS mRNA转录水平的影响。实验分为4组,即对照组(不含胰岛素)、正常浓度胰岛素组(含胰岛素1nmol/L)、恒定性高胰岛素组(含胰岛素100nmol/L)与波动性高胰岛素组(含胰岛素1nmol/L及含胰岛素100nmol/L两种条件培养液,每8小时轮换一次),每间隔8小时更换新鲜条件培养液一次,一共作用72小时。应用应用逆转录聚合酶链反应(RT-PCR)检测内皮细胞eNOS基因mRNA转录水平。结果:经不同浓度的胰岛素作用72小时后,正常浓度组、恒定性高胰岛素组与波动性高胰岛素组内皮细胞eNOS mRNA转录水平均不同程度上调,分别为对照组的2.25倍(p<0.001)、6.00倍(p<0.001)和6.88倍(p<0.001),其中以波动性高胰岛素组上调尤为明显,且明显高于恒定性高胰岛素组(p<0.05)。结论:波动性高胰岛素相对于恒定性高胰岛素能增强人脐静脉内皮细胞eNOS mRNA的转录。

Objective:To compare the effects of intermittent and constant high insulin media on the messenger ribonucleic acid(mRNA) transcription of endothelial nitric oxide synsase(eNOS) of cultured human umbilical endothelial cells line(HUECV304) so as to explore the mechanism of intermittent hyperinsulinemia on diabetic vascular complication.Methods:Human umbilical vein endothelial cells(EC) line were exposed for 72 hours to 0 nmol/L insulin(control),1 nmol/L insulin(nomal insulin),100 nmol/L insulin(constant high insulin) and 1nmol/L alternating with 100nmol/L insulin per 8 hours(intermittent high insulin) respectively.The eNOS mRNA expression was determined by RT-PCR.Results:In cultured HUECVs,exposure to normal insulin,constant high insulin and intermittent high insulin for 72 hours,caused a marked increase in the mRNA expression of eNOS.Compared with cells exposed to control media,the expressions of eNOS mRNA were increased to 2.25-folds(p<0.001),6.00-folds(p<0.001)and 6.88-folds(p<0.001)respectively,and the expression level of eNOS mRNA in intermittent high insulin was higher than that in constant high insulin(p<0.05).Conclusions:Compared with constant high insulin,intermittent high insulin further enhanced the mRNA transcription and then facilitating the development of chronic vascular complication in diabetes.