Atrial natriuretic peptide in newborn piglets with a patent ductus arteriosus

Atrial natriuretic peptide (ANP) is a hormone involved in fluid and blood pressure homeostasis. We studied the effects of left-to-right shunting through a patent ductus arteriosus on blood pressure changes and plasma ANP concentrations in newborn piglets. In five experimental piglets, the ductus arteriosus was bathed with PGE1 and infiltrated with formalin to maintain its patency. In four age-matched control piglets, the ductus arteriosus was ligated. Plasma ANP concentrations and blood pressure determinations were obtained prior to (base-line) and 25 +/- 1 h (day 1), and 48 +/- 1 h (day 2) after surgery. Radionuclide-microsphere determinations of left-to-right patent ductus arteriosus shunts were performed on days 1 and 2 in the 5 piglets with a patent ductus arteriosus. Plasma ANP concentrations were significantly elevated in the left atrium on day 1 and the right atrium on day 2 in the PDA piglets. No correlation was demonstrated between plasma ANP concentrations and right or left atrial pressures. We conclude that left and right plasma atrial ANP concentrations are significantly elevated in newborn piglets with left-to-right patent ductus arteriosus shunts.