MOLECULAR BIOLOGY AND BIOCHEMISTRY OF NATRIURETIC PEPTIDE FAMILY

The natriuretic peptide family consists of three endogenous ligands; atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP) and C‐type natriuretic peptide (CNP), and is involved in the regulation of cardiovascular homeostasis. Both ANP and BNP act mainly as cardiac hormones and are produced predominantly by the atrium and ventricle, respectively. Expression of the BNP and ANP genes is greatly augmented in patients with congestive heart failure and animal models of ventricular hypertrophy or cardiomyopathy. In the heart, the BNP gene expression is regulated differently from the ANP gene expression both at transcriptional and post‐transcriptional levels. Transgenic technology has provided the direct evidence that BNP as well as ANP is involved in the chronic blood pressure control. Contrasting with ANP and BNP, CNP does not act as a cardiac hormone but as a neuropeptide or an endothelium‐derived autocrine/paracrine regulator. Endothelial production of CNP is remarkably augmented by various cytokines and growth factors such as transforming growth factor‐β and tumour necrosis factor‐α, suggesting the pathophysiological significance of CNP in the process of various vascular disorders. Chromosomal mapping of natriuretic peptides has revealed that the CNP gene is localized on mouse chromosome 1, while ANP and BNP are tightly linked on mouse chromosome 4, suggesting that CNP, a local regulator, is functionally and evolutionarily distinct from ANP and BNP, both of which are cardiac hormones. Understanding the molecular biology and biochemistry of the natriuretic peptide family will lead to the better understanding of its physiological and pathophysiological implication, and the clinical application in cardiorenal regulation.