Serum atrial natriuretic peptide levels in infants with transient tachypnea of the newborn.

OBJECTIVE: The mechanisms responsible for lung liquid clearance during the neonatal period result in switching of the lung epithelium from net secretion to net absorption following birth and driven by active Na(+) absorption. Transient tachypnea of the newborn (TTN) is known as the most common consequence of inadequate neonatal lung liquid clearance. It has been reported that alveolar type II cells behaved as a target for atrial natriuretic peptide (ANP) which inhibits the amiloride-sensitive Na-channel activity. The objective of this study is to investigate serum ANP concentrations in infants with TTN. METHODS: Fourteen newborn infants who were diagnosed with TTN (gestational age; 35.6 +/- 2.0 weeks) and twenty healthy neonates (gestational age; 36.3 +/- 2.2 weeks) were included in the study. Serum pro ANP concentrations were measured by ELISA using Biomedica GmbH (AUSTRIA) proANP kit on the 4th and 72nd hours of life. RESULTS: The mean serum pro ANP concentration was 2996 fmol/ml at 4 and 2694 fmol/ml at 72 hours of age for the infants with TTN and mean serum pro ANP concentrations of healthy infants found 3301 fmol/ml (p = 0.34) and 3204 fmol/ml (p = 0.04), respectively. CONCLUSION: It is concluded that serum ANP concentrations decreased in infants with TTN.