Vasopeptidase inhibition: a new treatment approach for endothelial dysfunction.

Angiotensin-converting enzyme (ACE) inhibition is a well-established principle in the treatment of endothelial dysfunction. Numerous preclinical and clinical studies have clearly demonstrated the beneficial effects of inhibiting the renin-angiotensin-aldosterone system (RAS) in states of impaired endothelial function. The successful use of ACE inhibitors encouraged attempts to inhibit other key enzymes in the regulation of vascular tone, such as the neutral endopeptidase (NEP). Similar to ACE, NEP is an endothelial cell surface metalloproteinase that is involved in the degradation of several regulatory peptides, including the natriuretic peptides, and, thus, NEP inhibition augments vasodilatation and natriuresis through increased levels of atrial natriuretic peptide (ANP). By inhibiting the RAS and potentiating the natriuretic peptide system at the same time, combined NEP/ACE inhibitors, the so-called vasopeptidase inhibitors, reduce vasoconstriction and enhance vasodilatation, thereby decreasing peripheral vascular resistance and blood pressure. Within the vessel wall this may lead to a reduction of vasoconstrictor and proliferative mediators, such as angiotensin II and endothelin-1, and may increase local levels of bradykinin as well as natriuretic peptides. Even though first results of both preclinical and clinical studies indicate that combined inhibition of ACE and NEP by vasopeptidase inhibitors represents a promising strategy in the treatment of hypertension and heart failure, angioedema occurs more frequently on vasopeptidase inhibition as compared to ACE inhibition. To establish vasopeptidase inhibition as a novel option in the treatment of cardiovascular disease, further validation of efficacy and safety of this promising therapeutic principle is mandatory.