Prostaglandin E(2) (PGE(2)) is important in ductus arteriosus (DA) patency, but the types of functional PGE(2) receptors (EP) in the developing DA are not known. We postulated that age-dependent alterations in EP and/or their subtypes may possibly contribute to the reduced responsiveness of the newborn DA to PGE(2).
We determined PGE(2) receptor subtypes by competition binding and immunoblot studies on the DA of fetal ( approximately 75% and 90% gestation) and newborn (<45 minutes old) pigs. We studied the effects of EP receptor stimulation on cAMP signaling in vitro and on term newborn (<3 hours old) DA patency in vivo. Fetal pig DA expressed EP(2), EP(3), and EP(4) receptors equivalently, but not EP(1). In neonatal DA, EP(1), EP(3), and EP(4) were undetectable, whereas EP(2) density was similar in fetus and newborn. Prostaglandin-induced changes in cAMP mirrored binding data. 16,16-Dimethyl PGE(2) and 11-deoxy PGE(1) (EP(2)/EP(3)/EP(4) agonist) produced more cAMP in fetus than newborn, but butaprost (selective EP(2) agonist) caused similar cAMP increases in both; EP(3) and EP(4) ligands (M&B28767 and AH23848B, respectively) affected cAMP production only in fetus. After birth, administration of butaprost alone was as effective as 11-deoxy PGE(1) and 16,16-dimethyl PGE(2) in dilating DA in vivo.
The data reveal fewer PGE(2) receptors in the DA of the newborn than in that of the fetus; this may contribute to the decreased responsiveness of the DA to PGE(2) in newborn. Because EP(2) receptors seem to mediate the effects of PGE(2) on the newborn DA, one may propose that a selective EP(2) agonist may be preferred as a pharmacological agent to maintain DA patency in infants with certain congenital heart diseases.
This research output has an Altmetric Attention Score of 3. This is our high-level measure of the quality and quantity of online attention that it has received. This Attention Score, as well as the ranking and number of research outputs shown below, was calculated when the research output was last mentioned on 28 October 2008.
All research outputs
#7,558,767
of 23,057,470 outputs
Outputs from Circulation
#11,189
of 19,745 outputs
Outputs of similar age
#11,263
of 36,398 outputs
Outputs of similar age from Circulation
#48
of 114 outputs
Altmetric has tracked 23,057,470 research outputs across all sources so far. This one is in the 44th percentile – i.e., 44% of other outputs scored the same or lower than it.
So far Altmetric has tracked 19,745 research outputs from this source. They typically receive a lot more attention than average, with a mean Attention Score of 29.5. This one is in the 17th percentile – i.e., 17% of its peers scored the same or lower than it.
Older research outputs will score higher simply because they've had more time to accumulate mentions. To account for age we can compare this Altmetric Attention Score to the 36,398 tracked outputs that were published within six weeks on either side of this one in any source. This one is in the 9th percentile – i.e., 9% of its contemporaries scored the same or lower than it.
We're also able to compare this research output to 114 others from the same source and published within six weeks on either side of this one. This one is in the 13th percentile – i.e., 13% of its contemporaries scored the same or lower than it.
