PGE2/TXB2 imbalance in neonatal hypoxemic respiratory failure.
BACKGROUND
An imbalance of vaso-constrictor and -dilator mediators has been implicated in the pathogenesis of the pulmonary hypertension accompanying neonatal hypoxemic respiratory failure (NHRF).


OBJECTIVE
To characterize plasma PGE2, TXB2 and their ratio in normal newborns and in those with NHRF.


METHODS
Twenty newborns with NHRF received inhaled PGE1 (IPGE1) by jet nebulizer in doses of 25, 50, 150 and 300 ng/kg/min followed by weaning. Blood for PGE2 and TXB2 assay using EIA was available in 8 neonates with NHRF prior to IPGE1. Umbilical cord arterial samples were also obtained at delivery from 10 normal newborns to serve as controls.


RESULTS
Compared to normal newborns, those with NHRF had significantly lower PGE2/TXB2 ratios after controlling for preterm gestation (< 37 weeks) and postnatal age (p < 0.05). Notably, all subjects except one in the NHRF group had a value of < 1.0 (range 0.1-1.2) compared to a value of > 1.0 in all subjects in the Control group (range 1.1-5.2).


CONCLUSIONS
Lower PGE2/TXB2 ratio in subjects with NHRF compared with controls reflects a predominance of vaso-constrictor activity in these patients as the basis of pulmonary hypertension. Plasma PGE2/TXB2 ratio may have important implications for the diagnosis and treatment of NHRF.
Sood
B G
BG
Carman and Ann Adams Department of Pediatrics, Wayne State University, Hutzel Women's Hospital, 3901 Beaubien Blvd., Detroit, MI 48201, USA. bsood@med.wayne.edu
Delaney-Black
V
V
Glibetic
M
M
Aranda
J V
JV
Chen
X
X
Shankaran
S
S
D017321:Clinical Trials, Phase I as Topic; D017322:Clinical Trials, Phase II as Topic; D015232:Dinoprostone / Q000378:metabolism*; D005260:Female; D006801:Humans; D000860:Hypoxia / Q000378:metabolism* / Q000503:physiopathology; D007231:Infant, Newborn; D008297:Male; D010865:Pilot Projects; D012131:Respiratory Insufficiency / Q000378:metabolism* / Q000503:physiopathology; D013929:Thromboxane B2 / Q000378:metabolism*
D013929:Thromboxane B2; D015232:Dinoprostone