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

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.