Abstract:
Objective To investigate the effects of tetrahydrobiopterin(BH
4) on release of nitric oxide(NO) and superoxide anion (O
2-·) in human umbilical vein endothelial cells (HUVECs). Methods HUVECs were incubated with different concentration of D-glucose, insulin and BH
4, NOS, SOD activity, and the concentration of NO and O
2-· were measured in the supernatant. Results As compared with controls, NOS activity, the concentration of NO and O
2-· were elevated, while SOD activity was decreased in the HUVECs culture supernatant in the presence of 25 mmol/L D-glucose. In the presence of 10,100,1 000 mU/L insulin, NOS activity, the concentration of NO was increased, with little changes in SOD activity and O
2-·. BH
4 attenuated NOS activity, concentration of NO and decreased O
2-· with no change in SOD activity. Furthermore, BH
4 reverse of the elevated O
2-· induced by glucose. Conclusion BH
4 may increase NOS activity, induce NO generation and decreased the generation of O
2-·.