Effects of felodipine on the secretion of nitricoxide synthase and nitrogen monoxidum from human endothelial cells injuryed by oxidized low density lipoprotein

Objective: To investigate the protective effects of felodipine on mRNA levels of endothelial nitricoxide synthase (eNOS) and inducible nitricoxide synthase (iNOS) as well as the level of nitrogen monoxidum (NO) from human umbilical vein endothelial cells (HUVECs) injuryed by oxidized low density lipoprotein (ox-LDL). Methods: Isolated HUVECs were divided into blank control group, ox-LDL injury group treated with ox-LDL of different concentrations (6, 12.5 and 25 mg/L), and intervention group of felodipine (0.1, 1.0 and 10 μmol/L)+ox-LDL (25 mg/L). Then eNOS and iNOS expressions were measured by real time-polymerase chain reaction and the level of NO in the supernatants of the cultures was assayed by nitrate reductase method. Results: The mRNA expressions of eNOS and iNOS in HUVECs and NO level in the supernatants during treatment with different ox-LDL concentrations were higher than those in control group. However, felodipine significantly down-regulated the expression of iNOS in HUVECs injured by ox-LDL and inceased NO generation. Conclusion: Felodipine has protective effects on endothelial cells. The mechanism may be related to its lowering the mRNA expression of iNOS induced by low ox-LDL concentration and increasing NO production.