ATRIAL NATRIURETIC HORMONES ORIGINATING FROM THE N-TERMINUS OF THE ATRIAL-NATRIURETIC-FACTOR PROHORMONE

1. Four peptide hormones consisting of amino acids 1-30 (Long Acting S odium Stimulator), 31-67 (Vessel Dilator), 79-98 (Kaliuretic Stimulato r) and 99-126 (Atrial Natriuretic Factor [ANF]) originate from the sam e 126 amino acid ANF prohormone. 2. Each of these four peptide hormone s circulates as a distinct peptide with vessel dilator and long acting sodium stimulator circulating at 10- to 24-fold higher concentrations than ANF while kaliuretic stimulator circulates at a three-fold highe r concentration than ANF. 3. Each of these peptide hormones is release d with an increase in central volume causing stretch of the atrium of the heart and with rapid heart beats greater than 125 beats/min. 4. Ea ch of these peptide hormones lowers blood pressure, causes a diuresis and enhances sodium and/or potassium excretion. 5. In disease states w hich retain sodium and water such as congestive heart failure (CHF), e ach of these atrial peptides increases in the circulation proportionat ely to the severity of sodium retention, but of the radioinmunoassays to each of these hormones only the vessel dilator radioimmunoassay dif ferentiates between mild (class I) CHF and healthy individuals.