ANP is a hormone important in maintaining body fluid and sodium homeostasis. In cardiomyocytes, human ANP is synthesized as a 151-amino acid prepropeptide.

After the signal peptide is removed by the signal peptidase, pro-ANP is stored in the dense granules of the cell. On stimulation, pro-ANP is released from the dense granules and activated on the cell surface by proteolytic cleavage at residue arginine 98, generating an NH2-terminal propeptide and a 26-amino acid COOH-terminal peptide that is biologically active.

Plasma concentration of N-terminal atrial natriuretic peptide (Nt-proANP) is strongly directly related to salt sensitivity.In contrast to Nt-proANP, Nt-proBNP is not related to salt sensitivity. Salt sensitivity, as estimated by Nt-proANP, seems to be reduced in type 2 diabetes.