[Atrial natriuretic peptide. Mechanisms of its action]

A survey of the mechanisms of stimulation of secretion and of atrial natriuretic peptide (ANP) and its action is presented. Action of this hormone is particularly important on the kidney, the cardiovascular system and on some endocrine tissues. Major secretory organs are atrial myocytes, with an increased intra-atrial pressure as the stimulus. Under the action of ANP occurs dilatation of arterial blood vessels, often masked in vivo by a secondary increase in the sympathetic tone. ANP decreases the venous return with consecutive lowering of cardiac output. In a kidney an increase in diuresis and natriuresis occurs. Among the actions on the endocrine tissues inhibition of aldosterone secretion and, most probably, inhibition of renin secretion, are the most important.