In 1981, de Bold reported that injection of supernatants of atrial and ventricular myocardial homogenates into rats resulted in 30-fold increase of sodium and chloride excretions and 10-fold increase in urine volume [1]. This landmark discovery of atrial natriuretic peptides (ANP) was followed by characterization of B-type/Brain (BNP), C-type (CNP), Dendroaspis (DNP) and urodilantin (URO) natriuretic peptides (NP). NP have a highly preserved 17-amino acid (aa) cyclic structure constructed with disulfide bond.
