Endogenous peptide found in plasma and cerebrospinal fluid. Behaves as an agonist at natriuretic peptide receptor NPR2 (NPRB) and exhibits affinity for NPR3 (NPRC). Inhibits L-type calcium currents in myocytes and exhibits antiproliferative effects in cardiac fibroblasts in vitro. Regulates cartilage homeostasis, body fluid volume and exhibits vasodilatory activity in vivo.