CORRELATION BETWEEN BRAIN NATRIURETIC PEPTIDE AND ATRIAL NATRIURETIC PEPTIDE LEVELS IN NEONATAL PLASMA

Abstract

Brain natriuretic peptide (BNP), first discovered in porcine brain, is principally produced by the heart. Unlike atrial natriuretic peptide (ANP), BNP is largely derived from the ventricles. In adults plasma BNP levels, like ANP, respond to changes in blood volume and levels of 3,4-9.0 pg/ml have been reported. Fetal and cord blood BNP levels have been reported but we are not aware of further reports on BNP in neonates.We used specific radioimmunoassays (Peninsula Laboratories) to measure BNP and ANP levels in plasma from neonates with respiratory distress syndrome before and after treatment with exogenous surfactant. The cross reactivity between the two peptides in their respective assays is <0.001%.Results:Individual ANP and BNP levels were compared in 41 paired samples from babies aged 4 to 80 hours. ANP levels ranged from 87-2587 pg/ml and BNP levels ranged from 29-445 pg/ml. There was a strong correlation between the concentrations of the two peptides: R=0.76, p<0.0001 (Spearman's Rank Correlation test).Conclusions:We conclude that levels of BNP in the neonate are much higher than reported in adults and are highly correlated with ANP, although further work is needed to establish its physiological role.