16/10/2024
Brain natriuretic peptide was first isolated from pig brain by Japanese scholars and was named after it. It is mainly synthesized and secreted by myocardial cells and is a member of the natriuretic peptide (NP) family (including atrial natriuretic peptide-ANP, C-type natriuretic peptide-CNP, etc.).
It initially exists in the form of pro-BNP precursor containing 134 amino acids, which is cleaved by enzymes into inactive NT-proBNP containing 76 amino acids and physiologically active BNP containing 32 amino acids.
BNP is mainly degraded in large blood vessels and other areas, while NT-proBNP is mainly excreted through the kidneys. Measuring the level of BNP or NT-proBNP in plasma can diagnose and evaluate heart failure.
Although both BNP and NT-proBNP are derived from the equimolar cleavage of proBNP, they have different biological characteristics as shared picture.
In summary: BNP has a shorter half-life of about 20-22 minutes, which is more valuable in understanding the patient's immediate condition; NT-proBNP has a relatively longer half-life of 120 minutes, a higher concentration in peripheral blood, is more stable in vitro, and is more suitable for clinical monitoring.
BNP is affected by enkephalinase inhibitors (such as sacubitril), which reduces its degradation and increases its level; NT-proBNP is not affected.
In addition to being metabolized by the kidneys, BNP can also be cleared through receptor binding, enzymatic degradation and other pathways, and is relatively less affected by renal function. NT-proBNP is mainly metabolized by the kidneys and is more affected by renal function. At the same time, the NT-proBNP diagnostic threshold is more affected by age.
