Physiology and clinical significance of natriuretic hormones

The natriuretic system consists of the atrial natriuretic peptide (ANP) and four other similar peptides including the wrongly named brain natriuretic peptide (BNP). Chemically they are small peptide hormones predominantly secreted by the cardiac myocytes in response to stretching forces. The peptide hormones have multiple renal, hemodynamic, and antiproliferative effects through three different kinds of natriuretic receptors. Clinical interest in these peptide hormones was initially stimulated by the use of these peptides as markers to differentiate cardiac versus noncardiac causes of breathlessness. Subsequently work has been done on using these peptides to prognosticate patients with acute and chronic heart failure and those with acute myocardial infraction. Synthetic forms of both atrial- and brain-natriuretic peptides have been studied and approved for use in acute heart failure with mixed results. This review focuses on the biochemistry and physiology of this fascinating hormone system and the clinical application of these hormones.