Atrial natriuretic peptide in the preterm infant. Lack of correlation with natriuresis and diuresis.
We assessed the relation of atrial natriuretic peptide (ANP) to renal function on postnatal day 2 and day 5 in preterm infants. Plasma ANP concentration was measured by radioimmunoassay in two groups of preterm infants: group 1, gestational age less than 30 weeks, n = 10; and group 2, gestational age 30-34 weeks, n = 11. The identity of the immunoreactivity as ANP-28 was confirmed by HPLC. Plasma ANP was significantly higher in group 1 than in group 2 on day 2 and day 5 (p < 0.01) and ANP concentration decreased by day 5 in both groups (group 1, p < 0.01; group 2, p < 0.02). The results showed no correlation between plasma ANP concentration and urinary sodium excretion or creatinine clearance, which may be due to a blunted renal response to ANP, but other factors may be involved also. We conclude that preterm infants are able to release large amounts of ANP, but a high plasma ANP concentration does not correlate directly with renal regulation of sodium and water balance.
Ekblad
H
H
Department of Pediatrics, University of Turku, Finland.
Kero
P
P
Vuolteenaho
O
O
Arjamaa
O
O
Korvenranta
H
H
Shaffer
S G
SG
D009320:Atrial Natriuretic Factor / Q000097:blood*; D004231:Diuresis / Q000502:physiology*; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature / Q000502:physiology*; D007668:Kidney / Q000502:physiology*; D009318:Natriuresis / Q000502:physiology*
D009320:Atrial Natriuretic Factor