Atrial natriuretic peptide administration to normal and salt depleted rats--effects on digoxin-like immunoreactive factor, aldosterone, ACTH, and renal function.

In view of the known interrelationships between renin, aldosterone, and atrial natriuretic peptide (ANP), we sought to examine whether there also exists an interaction between ANP and digoxin-like immunoreactive factor (DLIF). We therefore studied the effects of ANP administration on normal and salt-depleted rats, and measured the effects on blood pressure, urine output, glomerular filtration rate, sodium excretion, aldosterone, ACTH, and DLIF levels. ANP administration resulted in a significant elevation of sodium excretion and glomerular filtration rate and a fall in blood pressure. DLIF concentrations in plasma rose significantly, as did urinary DLIF excretion. ANP administration resulted in a fall in aldosterone as well as ACTH. These observations suggest that ANP has a direct inhibitory effect on ACTH secretion. Our findings support the concept of an interrelationship between ANP and DLIF.