Nesiritide (Natrecor) is the recombinant form of the 32 amino acid human B-type natriuretic peptide, which is normally produced by the ventricular myocardium. Nesiritide works to facilitate cardiovascular fluid homeostasis through counterregulation of the renin–angiotensin–aldosterone system, stimulating cyclic guanosine monophosphate, leading to smooth muscle cell relaxation.