Anxiolytic activity of atrial natriuretic peptide (ANP)

Atrial natriuretic peptide (ANP) is not only synthesized by atrial myocytes and released into the circulation but is also found in the neurons of different brain regions, where specific binding sites have been found. In addition to its effects on water and salt intake ANP has neuroendocrine activity and attenuates the hypothalamic pituitary adrenocortical system. There is furthermore evidence for a behavioral activity of ANP: In the rat, central and peripheral administration of atriopeptin II, a 23-amino acid residue of ANP has been shown to be anxiolytic. Furthermore, the central nucleus of the amygdala was identified as one possible site of ANP anxiolytic activity. In humans ANP decreases cholecystokinin tetrapetide (CCK-4) induced panic anxiety and has been shown to be anxiolytic in patients with panic disorder. These results give preclinical and clinical evidence for an anxiolytic activity of ANP. Modulation of natriuretic peptide receptors may be ultimately used in the treatment of pathological anxiety.