炎症因子对胰岛素抵抗动物模型血管内皮细胞功能影响的研究

Effect of Inflammation Factors on Endothelial Function in Insulin Resistance SD Rats

目的探讨炎症因子在胰岛素抵抗状态下血管内皮细胞功能异常中的作用及可能的机理。方法 SD大鼠随机分为正常对照组(NC组)、肥胖组(OB组)和肥胖+阿司匹林干预组(OB-AS组)。NC组给予普通饲料喂养;OB组给予高脂饲料喂养;OB-AS组在给予高脂饲料喂养4周后,在高脂饲养的基础上每天给予200 mg/kg体质量的阿司匹林灌胃4周。应用正常葡萄糖高胰岛素钳夹试验评价外周胰岛素敏感程度;测定不同浓度乙酰胆碱(Ach)及硝普钠作用下股动脉血流速度的改变以评价血管内皮细胞依赖性舒张功能及非内皮细胞依赖性血管舒张功能;测定循环中肿瘤坏死因子-α(TNF-α)和C-反应蛋白(CRP)的水平;检测血管组织中核转录因子κB抑制蛋白激酶β-核因子-κB(IKKβ-NF-κB)分子通路的激活情况。结果 OB组血中TNF-α和CRP的水平较NC组升高(P<0.05),Ach刺激的血管舒张反应降低(P<0.05);血管舒张时血中一氧化氮(NO)水平低下(P<0.05)。血管组织NF-κBp65和IKKβ的染色强度明显增强,血管组织NF-κBp65的表达是NC组的1.7倍(P<0.05)。与OB组比较,OB-AS组其炎症因子水平下降(P<0.05),给予Ach后血中NO水平增加(P<0.05),血管舒张强度增加(P<0.05)。OB-AS组血管组织NF-κBp65和IKKβ的染色强度、内皮细胞NF-κBp65的表达水平较OB组下降(P<0.05)。结论胰岛素抵抗状态下循环中增多的炎症因子通过激活经典的IKKβ-NF-κB分子通路导致内皮源性NO产生减少,可能是胰岛素抵抗状态下血管内皮细胞功能异常的分子机理之一。

Objective To test the effect of inflammation factors on endothelial dysfunction in insulin resistance SD rats.Methods Male SD rats were divided randomly into three groups.The rats in the NC group,OB group and OB-AS group were fed with normal chow,high-fat chow,and high fat chow plus aspirin,respectively.The perifereal insulin sensitivity was detected with hyperinsulinemic euglycemic clamp.The endothelial dependent and independent vasodilatation were evaluated by measuring blood flow through femoral artery.Serum concentrations of high-sensitivity（hs） CRP and TNF-α were measured.Quantitative analysis of the expression of IKKβ and NF-κB was performed.Results The rats in the OB group had significantly higher levels of serum hsCRP and TNF-α than the rats in the NC group（P〈0.05）.There was a significant difference in endothelium-dependent（Ach-mediated dilation） vascular response and serum NO level between the OB group and the NC group（P〈0.05）.Meanwhile,the rats in the OB group showed higher expression of NF-κBp65（P〈0.05） and IKKβ/NF-κBp65（P〈0.05） than those in the NC group.Interestingly,compared with the rats in the OB group,the serum concentrations of TNF-α and CRP decreased significantly in the rats in the OB-AS group,to which high dose aspirin was given（P〈0.05）.Better endothelium-dependent vascular response and higher serum NO level were observed in the rats in the OB-AS group than those in the NC group（P〈0.05）.The rats in the OB-AS group also had significantly lower expression of NF-κBp65（P〈0.05） and IKKβ/NF-κBp65（P〈0.05） than those in the OB group.Conclusion Elevated inflammation factors are involved in the endothelial dysfunction by inactivating IKKβ-NF-κB pathway in rats with insulin resistance.