Are the atrial peptides a natriuretic hormone?

Abstract

The control of sodium balance plays a vital role in the regulation of both intravascular and extravascular fluid volume. The discovery and synthesis of the atrial natriuretic peptides has led to the suggestion that they may be an important hormone in the control of sodium and water balance. Studies in man have confirmed that, when injected, they are natriuretic and that the plasma level, as measured by radioimmunoassay, changes with physiological changes in extracellular volume particularly those that occur with alteration of salt intake, the levels of atrial peptide rising as salt intake is increased. A recent study with a low dose infusion of atrial peptides has shown an increase in sodium excretion at the same plasma levels as those found with saline infusion, confirming that the atrial peptides are a natriuretic hormone in man. These findings allow a better interpretation of the raised levels that are already being described in patients with heart failure, renal failure and high blood pressure.