Hypertension, or high blood pressure, is a common disease that affects many Americans, and can lead to devastating consequences such as heart attack, stroke, and death if not treated. Nebivolol is a medication that has been recently approved by the FDA for the treatment of hypertension. Nebivolol has an unusual profile compared to other medications, in that its effects may be related to release of a substance called nitric oxide. Nitric oxide is released from the cells lining the blood vessels, and nebivolol may stimulate these cells to release more nitric oxide. Our study will investigate whether treatment with nebivolol, as compared to another medication called metoprolol, in hypertensive subjects will be more effective in protecting blood vessels against the harmful effects of high blood pressure. The mechanisms we will investigate include oxidative stress markers and circulating levels of endothelial progenitor cells.