Abstract
The natriuretic peptide (NP) system is composed of 3 distinct peptides (atrial natriuretic peptide or ANP, B-type natriuretic peptide or BNP, and C-type natriuretic peptide or CNP) and 3 receptors (natriuretic peptide receptor-A or NPR-A or particulate guanynyl cyclase-A natriuretic peptide receptor-B or NPR-B or particulate guanynyl cyclase-B, and natriuretic peptide receptor-C or NPR-C or clearance receptor). ANP and BNP function as defense mechanisms against ventricular stress and the deleterious effects of volume and pressure overload on the heart. Although the role of NPs in cardiovascular homeostasis has been extensively studied and well established, much remains uncertain about the signaling pathways in pathological states like heart failure, a state of impaired natriuretic peptide function. Elevated levels of ANP and BNP in heart failure correlate with disease severity and have a prognostic value. Synthetic ANP and BNP have been studied for their therapeutic role in hypertension and heart failure, and promising trials are under way. In recent years, the expression of ANP and BNP in human adipocytes has come to light. Through their role in promotion of adipocyte browning, lipolysis, lipid oxidation, and modulation of adipokine secretion, they have emerged as key regulators of energy consumption and metabolism. NPR-A signaling in skeletal muscles and adipocytes is emerging as pivotal to the maintenance of long-term insulin sensitivity, which is disrupted in obesity and reduced glucose-tolerance states. Genetic variants in the genes encoding for ANP and BNP have been associated with a favorable cardiometabolic profile. In this review, we discuss several pathways that have been proposed to explain the role of NPs as endocrine networkers. There is much to be explored about the therapeutic role of NPs in improving metabolic milieu.