Abstract 859: Nifedipine Improves Endothelial Function in Patinets with Hypertension: Role of Endothelial Progenitor Cells
Nifedipine, a calcium channel blocker, has been shown to improve endothelial function. Recent studies have indicated that endothelial function is correlated with the number of circulating endothelial progenitor cells (EPCs), but it is unclear whether nifedipine affects the number and function of EPCs. The aim of this study was to determine the effects of nifedipine on the number and function of EPCs, and to investigate the relationship between improvement of endothelial function and EPC numbers in patients with hypertension. Stage 1 hypertensive men (n=37) were randomly divided into the nifedipine group and the control untreated group. The nifedipine group was administered slow-release nifedipine (20 mg) once daily. At baseline and after 4 weeks, flow-mediated dilation (FMD), blood pressure, biochemical data, and number of circulating CD34+CD133+ progenitor cells (CPCs) and EPCs were measured. The direct effects of nifedipine on EPC number and function were assessed in vitro. In the nifedipine group, FMD and the numbers of CPCs and EPCs were increased, along with a decrease of serum malondialdehyde-LDL. The improvement of FMD by nifedipine was correlated with the increase of CPCs. Nifedipine also improved angiogenesis-related functions of EPCs (differentiation, migration, and resistance to oxidative stress) in vitro. Thus, nifedipine improved endothelial function and EPC function in stage 1 hypertensive subjects. The latter action may be mediated by reduction of oxidative stress and suppression of EPC apoptosis. These results demonstrate that nifedipine preserves endothelial integrity in patients with hypertension, at least partly, by enhancing EPC numbers and activity.