Umbilical venous guanosine 3',5'-cyclic phosphate (cGMP) concentration increases in asphyxiated newborns.
Guanosine 3',5'-cyclic phosphate (cGMP) is known to be the second messenger of natriuretic peptides and nitric oxide (NO). To investigate the involvement of natriuretic peptides in the regulation of the feto-placental circulation, specific radioimmunoassays were used to measure the concentrations of atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP) and cGMP in the umbilical venous plasma of normal and asphyxiated newborns. The plasma concentrations of ANP, BNP and cGMP in asphyxiated newborns were 48.3 +/- 12.9 pm, 24.5 +/- 9.4 pm and 4.4 +/- 1.6 nM (mean +/- s.e.m., n = 10), respectively. These values were significantly higher than those in the normal newborns (17.4 +/- 1.9 pm, 4.7 +/- 1.0 pm, and 0.78 +/- 0.14 nM, respectively). Moreover, the expression of both ANP-A and ANP-B receptor, biologically active receptors for natriuretic peptides, was detected in term human placenta by Northern bolt analysis. The expression of natriuretic peptide receptors was further confirmed by binding assay using [125I]-labelled ANP and solubilized crude membrane preparations of placental tissue. These findings suggest that cGMP is produced in the placenta, at least partly, by the action of ANP and BNP secreted from fetal heart, in pathophysiological conditions such as fetal hypoxia.
Itoh
H
H
Department of Gynaecology and Obstetrics, Kyoto University Faculty of Medicine, Japan.
Sagawa
N
N
Hasegawa
M
M
Mori
T
T
Suga
S
S
Mukoyama
M
M
Yoshimasa
T
T
Itoh
H
H
Nakao
K
K
D001238:Asphyxia Neonatorum / Q000097:blood*; D009320:Atrial Natriuretic Factor / Q000097:blood; D001483:Base Sequence; D015152:Blotting, Northern; D002462:Cell Membrane / Q000378:metabolism; D006152:Cyclic GMP / Q000097:blood*; D006801:Humans; D007231:Infant, Newborn; D008969:Molecular Sequence Data; D020097:Natriuretic Peptide, Brain; D009419:Nerve Tissue Proteins / Q000097:blood; D010920:Placenta / Q000737:chemistry / Q000378:metabolism; D017461:Receptors, Atrial Natriuretic Factor / Q000032:analysis / Q000378:metabolism; D012016:Reference Values; D014471:Umbilical Veins
D009419:Nerve Tissue Proteins; C058930:brain natriuretic peptide receptor; D020097:Natriuretic Peptide, Brain; D009320:Atrial Natriuretic Factor; D017461:Receptors, Atrial Natriuretic Factor; D006152:Cyclic GMP