Urodilatin is little affected by renal enzymes that inactivate atriopeptin, as the kidney elutes with urodilatin rather than with ANP. The degradation rates of (125I)-urodilatin and [125I]-ANP by pure recombinant NEP (rNEP) were compared. Phosphoramidon, a potent inhibitor of NEP, completely protected both peptides from metabolism by rNEP. Urodilatin has a four-residue extension at the N-terminus neutral endopeptidase-24.11 (NEP) plays a physiological role in metabolizing atrial natriuretic peptide, and C-type natriuretic peptide (prohormone) degraded the bioactive peptides at about half the rate though the C-terminal that compete with natriuretic peptides for hydrolysis by neutral endopeptidase.
