title: B-type Natriuretic Peptide circulating forms: Analytical and bioactivity issues.
abstract: B-type Natriuretic Peptide (BNP), A-type and C-type Natriuretic Peptides (ANP and CNP) comprise a family of peptides that retain a common ring structure and conserved amino acid sequences. All are present in the heart, but only BNP and ANP are regarded as primarily cardiac secretory products. BNP and ANP, acting through a guanylyl cyclase receptor, increase sodium and water excretion by the kidney, induce vasodilation, reduce blood pressure, counteract the bioactivity of the renin-angiotensin-aldosterone and sympathetic nervous systems and possess anti-hypertrophic and anti-fibrotic properties. BNP is synthesised in cardiomyocytes first as the precursor peptide preproBNP. Removal of the signal peptide from preproBNP produces proBNP which is cleaved to produce the biologically active carboxy-terminal BNP peptide and the inactive N-terminal fragment, NT-proBNP. BNP, NT-proBNP, proBNP and the C-terminal portion of the BNP signal peptide have been detected in human plasma as well as multiple sub-forms including truncated forms of BNP and NT-proBNP, as well as variable glycosylation of NT-proBNP and proBNP. The origin of these circulating forms, their potential bioactivity and their detection by current analytical methods are presented in this review.
authors.affiliation: Department of Medicine, Christchurch Heart Institute, University of Otago, Christchurch, 2 Riccarton Avenue, Christchurch 8140, New Zealand. Electronic address: tim.yandle@otago.ac.nz.
authors.forename: Tim G
authors.initials: TG
authors.lastname: Yandle
authors.affiliation: Department of Medicine, Christchurch Heart Institute, University of Otago, Christchurch, 2 Riccarton Avenue, Christchurch 8140, New Zealand; Cardiac Department, Cardiovascular Research Institute, National University Heart Centre, National University of Singapore, 1E Kent Ridge Road, NUHS Tower Block, Level 9, Singapore 119228, Singapore.
authors.forename: A Mark
authors.initials: AM
authors.lastname: Richards
mesh_terms: D006031:Glycosylation; D006801:Humans; D007118:Immunoassay; D020097:Natriuretic Peptide, Brain / Q000032:analysis* / Q000378:metabolism*
chemical_list: D020097:Natriuretic Peptide, Brain
keywords: BNP; Glycosylation; NT-proBNP; Natriuretic peptide; Truncation; proBNP