An endogenous peptide with cardiovascular functions; an agonist of NPR1/GC-A and NPR3 (Kd = 7.3 and 13 pM, respectively, for human chimeric extracellular receptors); binds human recombinant NPR1/GC-A and NPR3 (IC50s = 8 and 2.6 nM, respectively); activates NPR1/GC-A and increases cGMP levels in HEK293 cells (EC50 = 27 nM); stimulates cGMP accumulation in bovine aortic endothelial and aortic smooth muscle cells (EC50s = 9 and 17 nM, respectively); relaxes PGF2α-induced contractions in isolated porcine coronary artery and rat aortic strips (IC50s = 0.02 and 12.1 nM, respectively); increases mean urine flow and the sodium excretion rate in rats (10 nmol/kg)