Atrial Natriuretic Peptide

Atrial natriuretic peptide (ANP) is the first hormone isolated from the heart as a potent natriuretic/diuretic and hypotensive factor. ANP has an intra-molecular ring structure connected by two cysteine residues and N-terminal and C-terminal extensions from it. ANP is present in mammals, amphibians and bony fishes, but absent in birds, reptiles, cartilaginous fishes, and cyclostomes. ANP induces profound natriuresis/diuresis, hypotension, and inhibition of aldosterone secretion in mammals and amphibians. In teleost fish, ANP is a hypotensive hormone but its osmoregulatory effect is more versatile. In eels, ANP potently inhibits drinking and intestinal NaCl absorption, exerts a weak antidiuretic effect and stimulates cortisol secretion, all of which promote seawater adaptation. In human, ANP is an important target for diagnosis and treatment of heart failure. ANP knockout results in salt-sensitive hypertension.