SECRETION AND RENAL EFFECTS OF ANF PROHORMONE PEPTIDES

1. Atrial natriuretic factor (ANF) and pro ANF peptides appear to be s ecreted simultaneously from the atria in response to atrial stretch. 2 . The major peptide forms secreted from rat atria appear to be ANF (pr o ANF 99-126) as the primary C-terminal peptide and pro ANF 1-30 as th e primary N-terminal peptide, as opposed to 1-67 or 1-98. 3. The plasm a concentrations of ANF and pro ANF 1-30 are increased by acute stimul ation with blood volume expansion and the plasma levels of ANF and N-t erminal ANF prohormone peptides are chronically elevated by high salt diet. 4. Pro ANF 31-67 produces a natriuresis which is not dependent o n an increase in renal cGMP excretion, decreases in plasma renin activ ity (PRA) or elevations in plasma ANF concentration.