BNP (Brain Natriuretic Peptide)
Cardiovascular / RenalAlso known as: Brain Natriuretic Peptide, B-type Natriuretic Peptide, BNP-32, Nesiritide Endogenous
Mechanism
BNP (B-type natriuretic peptide) is released by the heart ventricles when they are under stress or stretched by fluid overload. Despite its confusing name (it was first found in brain tissue), it is primarily a cardiac hormone. BNP and its stable fragment NT-proBNP are the most widely used blood tests for diagnosing and monitoring heart failure. Recombinant BNP (nesiritide) is an FDA-approved drug for acute decompensated heart failure.
Technical detail
BNP is a 32-amino-acid cyclic peptide (Cys10-Cys26 disulfide ring) secreted predominantly by ventricular cardiomyocytes in response to myocardial wall stress and volume overload. Encoded by NPPB gene, it is synthesized as pre-proBNP, cleaved to proBNP-108, then to active BNP-32 and inactive NT-proBNP-76 by corin and furin. BNP binds NPR-A (GC-A), generating cGMP-PKG signaling identical to ANP effects: natriuresis, vasodilation, RAAS suppression, and anti-hypertrophic/anti-fibrotic cardiac effects. NT-proBNP (half-life ~120 min vs. ~20 min for BNP) is the preferred clinical biomarker for HF diagnosis and risk stratification.