Description
Introduction: Brain natriuretic peptide (BNP, also known as B-type natriuretic peptide or "GC-B") is a natriuretic hormone that is similar to ANP. It is a 32-amino-acid polypeptide secreted by the ventricles of the heart in response to excessive stretching of myocytes (heart muscles cells). Cardiac natriuretic hormones (CNHs) are a family of related peptides, including atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), and other peptides derived from the N-terminal portion of the proANP and proBNP peptide chains. Brain natriuretic peptide (also known as B-type natriuretic peptide or "GC-B") is a 32 amino acid polypeptide secreted by the ventricles of the heart in response to excessive stretching of myocytes (heart muscles cells) in the ventricles. At the time of release, a co-secreted 76 amino acid N-terminal fragment (NT-proBNP) is also released with BNP. BNP binds to and activates NPRA in a similar fashion to atrial natriuretic peptide (ANP) but with 10-fold lower affinity. The biological half-life of BNP, however, is twice as long as that of ANP. Both ANP and BNP have limited ability to bind and activate NPRB. Brain natriuretic peptide was originally identified in extracts of porcine brain, but in humans it is produced mainly in the cardiac ventricles. Physiologic actions of BNP and ANP include decrease in systemic vascular resistance and central venous pressure as well as an increase in natriuresis. Thus, the resulting effect of these peptides is a decrease in cardiac output and a decrease in blood volume. BNP is a valuable marker in heart failure and its therapy, for example cardiac resynchronization therapy.
Principle of the Assay: The microtiter plate provided in this kit has been pre-coated with an antibody specific to BNP. Standards or samples are then added to the appropriate microtiter plate wells with a biotin-conjugated polyclonal antibody preparation specific for BNP. and Avidin conjugated to Horseradish Peroxidase (HRP) is added to each microplate well and incubated. Then a TMB (3,3'5, 5' tetramethyl-benzidine) substrate solution is added to each well. Only those wells that contain BNP., biotin-conjugated antibody and enzyme-conjugated Avidin will exhibit a change in color. The enzyme-substrate reaction is terminated by the addition of a sulphuric acid solution and the color change is measured spectrophotometrically at a wavelength of 450 nm +/- 2 nm. The concentration of BNP. in the samples is then determined by comparing the O.D. of the samples to the standard curve