Effects of homocysteine on the expression of eNOS and the production of NO in the human umbilical veins endothelial cells

Objective To investigate the effects of homocysteine on the expressions of eNOS and the production of NO in the human umbilical veins endothelial cells(HUVECs) and explore the role of homocysteine in the development of atherosclerosis.Methods The HUVECs were randomly divided into 5 groups,and each group was cultured with 0,2.5,5,10,15 mmol/L Hcy for 24 hours.MTT assay was used to detect cell viability.The expression of eNOS mRNA was tested by RT-PCR.The method of nitric acid reductase was used to measure the concentration of nitric oxide.Results After HUVECs were exposed to Hcy at different concentrations(5～15 mmol/L),the HUVECs were inhibited compared with the control group(P0.05,P0.01) and the expression of eNOS mRNA was reduced significantly in a dose-dependent manner compared with the control group(P0.01).The production of NO was reduced significantly dose-dependently compared with the control group(P0.01).Conclusions Hcy can result in the downregulation of eNOS mRNA,reduce the synthesis of eNOS and then decrease eNOS activity.As a result,Hcy could reduce the production of NO in HUVECs.