[Atrial natriuretic peptide. I: Biochemistry, general pharmacology and physiology. A review].

The recent discovery of the atrial natriuretic peptide (ANP) system and its possible physiological role in mammalians is discussed. The atrium is the major site of synthesis for ANP, where it is stored in specific secretory granules of atrial myocytes as a 126 amino acid precursor molecule (ANP 1-126). Upon adequate stimuli, such as atrial distension, the biologically active ANP (99-126) is released into the circulation. The hormone binds to specific receptors of the target organs, provoking natriuresis, diuresis, vasodilatation and exerts an inhibitory effect on the renin-angiotensin-aldosterone system. The peptide seems to play a role in cardiovascular regulation by both its renal and extrarenal actions.