Beta blockers, nitric oxide, and cardiovascular disease.

The third generation β-blockers possess important ancillary properties besides inhibiting β-adrenoceptors. Among them, nebivolol activates nitric oxide synthase (NOS). Nebivolol and carvedilol preserve NOS activity by reducing asymmetrical dimethylarginine (AMDA) and enhance the bioavailability of nitric oxide (NO) because of their antioxidant properties. Concerning the treatment of hypertension and chronic heart failure, these third generation β-blockers show distinct advantages resulting from their NO-dependent effects (vasodilatation, anti-proliferation and cardioprotection), which may translate into a more effective clinical outcome than that obtained with the conventional β-blockers. Impaired NOS activity and reduced NO bioavailability are common initiators of cardiovascular dysfunction. Thus, owing to their NO-mediated actions, the new generation β-blockers should find more clinical applications in the treatment of cardiovascular diseases.