Fenofibrate re-couples endothelial nitric oxide synthase by restoring the level of tetrahydrobiopterin in human umbilical vein endothelial cells

Objective To investigate whether fenofibrate could re-couple endothelial nitric oxide synthase(eNOS).Methods Human umbilical vein endothelial cells(HUVECs) were treated with fenofibrate for 2 hours,after that the cells were incubated with lipopolysaccharide(LPS) for 24 hours.The amount of intracellular tetrahydrobiopterin(BH4) was measured by high-performance liquid chromatography.The levels of intracellular eNOS and cell culture supernatant nitric oxide(NO) were measured by ELISA kits.A confocal laser scanning microscope was used to detect the level of intracellular reactive oxygen species(ROS).Results Compared with control group,the levels of BH4,eNOS and NO were lower in LPS group,and ROS level was higher(P0.05).The levels of BH4,eNOS and NO in pretreated group with fenofibrate were significantly higher than those in LPS group(P0.05),the level of ROS was lower than that in LPS group(P0.05).Conclusion Fenofibrate may protect against atherosclerosis by promoting the re-coupling of eNOS with increasing the level of BH4.