Atrial Natriuretic Peptide in Umbilical Cord Blood: Evidence for a Circulating Hormone in Human Fetus

We have identified recently a new peptide, NT-proCNP(1–50) (N-terminal pro-C-type natriuretic peptide), in the circulation of humans and sheep. A previous report of an elevated fetal–maternal gradient in immunoreactive CNP raised the possibility that processing and metabolism of proCNP may differ in maternal and fetal tissues. We therefore collected matching peripheral maternal and umbilical cord plasma samples at delivery from women with normotensive and pre-eclamptic pregnancies to investigate the presence and concentrations of CNP and NT-proCNP using HPLC and RIA. Plasma concentrations of NT-proCNP in normotensive umbilical cord plasma were 10-fold higher than maternal venous levels (246±17 compared with 24.3±1.8 pmol/l; P<0.001) and much higher than corresponding levels of CNP (3.6±0.4 compared with 1.8±0.3 pmol/l in the fetal and maternal plasma respectively; P<0.001). Although there was no significant difference between normotensive and pre-eclamptic plasma CNP concentrations in either maternal or umbilical cord blood, NT-proCNP showed a significant statistical interaction (F=5.8, P=0.025) between the source (maternal or fetal) and gestational group (normotensive or pre-eclamptic). Maternal NT-proCNP levels were raised in the pre-eclampsia group, whereas the converse was observed in umbilical cord blood. In conclusion, the greatly elevated ratio of NT-proCNP/CNP in fetal compared with maternal plasma suggests that synthesis, as well as clearance, of CNP (but not NT-proCNP clearance) are markedly increased in fetal tissues.

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N-Terminal Pro-B-Type Natriuretic Peptide Concentrations Are Markedly Higher in the Umbilical Cord Blood of Newborns than in Their Mothers

Clinical Chemistry ◽

10.1373/clinchem.2004.046557 ◽

2005 ◽

Vol 51 (5) ◽

pp. 913-915 ◽

Cited By ~ 25

Author(s):

Angelika Hammerer-Lercher ◽

Johannes Mair ◽

Gernot Tews ◽

Bernd Puschendorf ◽

Rudolf Sommer

Keyword(s):

Cord Blood ◽

Natriuretic Peptide ◽

Umbilical Cord ◽

Umbilical Cord Blood

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Umbilical cord blood amino-terminal pro-brain natriuretic peptide levels according to the mode of delivery

Archives of Gynecology and Obstetrics ◽

10.1007/s00404-009-1253-3 ◽

2009 ◽

Vol 281 (5) ◽

pp. 907-912 ◽

Cited By ~ 11

Author(s):

Won Joon Seong ◽

Douk Hun Yoon ◽

Gun Oh Chong ◽

Dae Gy Hong ◽

Tae Bon Koo ◽

...

Keyword(s):

Brain Natriuretic Peptide ◽

Cord Blood ◽

Natriuretic Peptide ◽

Umbilical Cord ◽

Umbilical Cord Blood ◽

Mode Of Delivery ◽

Amino Terminal

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Heterogeneous binding sites for alpha-atrial natriuretic peptide in human umbilical cord and placenta

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.1991.261.3.r633 ◽

1991 ◽

Vol 261 (3) ◽

pp. R633-R638

Author(s):

S. P. Salas ◽

R. F. Power ◽

A. Singleton ◽

J. Wharton ◽

J. M. Polak ◽

...

Keyword(s):

Atrial Natriuretic Peptide ◽

Natriuretic Peptide ◽

Umbilical Cord ◽

Binding Sites ◽

Umbilical Artery ◽

Dissociation Constants ◽

Umbilical Vein ◽

Placental Tissue ◽

Human Umbilical Cord ◽

Atrial Natriuretic

The distributions of atrial natriuretic peptide (ANP) clearance receptors in human umbilical cord and placenta were investigated by using des[Gln18,Ser19,Gly20,Leu21,Gly22]ANP-(4-2 3) (C-ANP) as a specific ligand of this receptor to displace bound alpha-125I-labeled ANP. alpha-125I-ANP bound reversibly to umbilical venous and arterial intima and to fetal placental and maternal decidual tissues, with dissociation constants of 1.24 +/- 0.51, 0.58 +/- 0.19, 1.86 +/- 0.51, and 1.07 +/- 0.25 mM, respectively. Binding was reversed by 1 microM unlabeled alpha-ANP but not by unrelated peptides such as gastrin. The 1 microM C-ANP displaced bound alpha-125I-ANP from the intima of umbilical artery but not that of the vein. The specific reversible binding of alpha-125I-ANP to placental decidua but not to fetal placenta was also displaced by 1 microM C-ANP. Therefore high-affinity binding sites for alpha-ANP on the intima of the umbilical artery and on placental decidua differ from those on the umbilical vein and on fetal placental tissue; the binding sites of the intima of the umbilical artery and of the decidua in humans are consistent with clearance receptors for alpha-ANP.

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