To determine if a correlation exists between EPC function and eNOS-dependent NO production in EPCs from populations with high versus low cardiovascular risk:
1. High and low cardiovascular risk subjects will be identified based on age or history of cardiovascular disease. Endothelial function will be measured by ultrasound.
2. EPCs will be isolated from peripheral blood of these subjects. EPC function will be assessed by measuring adhesion to endothelium, migration, proliferation, and differentiation, and compared to their expression and activity of eNOS.
