A review.Urodilatin, a natriuretic peptide with four addnl. amino acids compared to atrial natriuretic peptide (ANP), is generated in distal tubule cells of the renal nephron.Whereas the fundamental role of ANP in the kidney, namely the regulation of natriuresis and diuresis, is questionable, urodilatin may be responsible for this task when secreted into the lumen of the distal tubule.More stable than ANP, it can act as a paracrine regulator and bind to its specific receptors located in the luminal membrane of cortical collecting duct (CCD) and inner medullary collecting duct (IMCD), thus, displaying its effects on cellular pH, Na+ transport, and H2O homeostasis.Urodilatin might also play a future role in the treatment of acute decompensated heart failure, acute renal failure, and bronchial asthma.