Natriuretic peptide: One of the peptides that causes natriuresis, the excretion of an excessively large amount of sodium in the urine. The natriuretic peptides are produced by the heart and vasculature:
- A-type natriuretic peptide is secreted largely by the atrial myocardium in response to dilatation.
- B-type natriuretic peptide is manufactured mainly by the ventricular myocardium.
- C-type natriuretic peptide is produced by endothelial cells that line the blood vessels.
B-type natriuretic peptide is useful in the diagnosis of heart failure. The finding of a low level of B-type natriuretic peptide tends to exclude heart failure.