Atrial Natriuretic Peptide (ANP) causes

(A) | Blood volume# Atrial distention and/or a sodium load cause release into the circulation of atrial natriuretic peptide (ANP), a polypeptide; a high-molecular-weight precursor of ANP is stored in secretory granules within atrial myocytes.> Release of ANP causes:> Excretion of sodium and water by augmenting glomerular filtration rate, inhibiting sodium reabsorption in the proximal tubule, and inhibiting release of renin and aldosterone; and> Arteriolar and venous dilatation by antagonizing the vasoconstrictor actions of All, AVP, and sympathetic stimulation. Thus, ANP has the capacity to oppose sodium retention and arterial pressure elevation in hypervolemic states.# ANP is secreted in response to: Stretching of the atrial wall Reduced Sympathetic stimulation of b-adrenoceptors Raised sodium concentration (hypernatremia), though sodium concentration is not direct stimulus for increased ANP secretion Angiotensin-II Endothelin, a potent vasoconstrictor Exercise