二氮嗪预处理对缺氧复氧大鼠心肌微血管内皮细胞HIF-1α mRNA表达及增殖的影响

The effects of diazoxide pretreatment on the expression of HIF-1α mRNA in rats cardiac microvascular endothelial cells exposed to hypoxia-reoxygenation

目的:观察二氮嗪(DZ)预处理对缺氧复氧大鼠心肌微血管内皮细胞(MMECs)增殖和HIF-1 α mRNA表达的影响。方法:培养SD大鼠MMECs,随机分为4组(n=24):正常对照组(N组)、缺氧/复氧组(H/R组)、二氮嗪组(DZ组)、DZ+Mito KATP特异性阻断剂5-羟葵酸(5-HD)预处理组(DZ+5-HD组)。DZ组加入100μmol/L DZ,DZ+5-HD组加入100μmol/L DZ前2 h加入100μmol/L 5-HD预处理2 h,然后和缺氧复氧组同样进行缺氧2 h复氧2 h。Hoechst染色观察凋亡细胞形态,MTT法测定细胞活力,RT-PCR检测HIF-1α mRNA转录水平。结果与N组比较,细胞增殖率H/R组显著降低(P<0.01),HIF-1α显著升高(P<0.01);与H/R组比较,DZ组细胞增殖率显著升高(P<0.05),HIF-1α显著升高(P<0.01);DZ+5-HD组与H/R组比较差异无统计学意义。结论:DZ可上调HIF-1αmRNA的表达,促使细胞增殖,从而实现促进心肌微血管的新生。

Objective： To investigate the effects of diazoxide pretreatment on the expression of HIF-1α mRNA and proliferation rate in rat cardiac microvascular endothelial cells exposed to hypoxia-reoxygenation（H/R）.Methods： The SD rat cardiac microvascular each.The normal control group（group N） without any disposal,the cells of H/R group,diazoxide pretreatment group（group DZ） and endothelial cells were cultured and randomly divided into 4 groups（n=24） diazoxide pretreatment ＋ mitochondrial ATP-sensitive potassium channel blocker 5-hydroxydecanoate（5-HD） group（group DZ＋5-HD） were exposed to 2 h hypoxia followed by 2 h reoxygenation.Diazoxide 100 μmol/L and diazoxide 100 μmol/L＋ 5-HD 100 μmol/L were added to the cultured medium 2 h before hypoxia in group DZ and DZ＋5-HD respectively.Results： Compared with group N,the cell proliferation rate significantly decreased（P0.01）.The expression of HIF-1α mRNA（P0.01） was up-regulated in H/R group.Compared with group H/R,the cell proliferation rate significantly increased（P0.05）.The expression of HIF-1α mRNA was up-regulated（P0.01） in group DZ.5-HD could inhibit diazoxide pretreatment-induced changes mentioned above（P0.05）.There were no difference compared with group H/R.Conclusion： Diazoxide pretreatment can up-regulate the expression of HIF-1α mRNA of rat cardiac microvascular endothelial cells,prompted cell proliferation and bringed about the neogenesis of rat cardiac microvascular.