Administration of antenatal glucocorticoids prevents pulmonary artery structural changes in nitrofen-induced congenital diaphragmatic hernia in rats.
OBJECTIVE
The aim of this study was to investigate whether maternal administration of dexamethasone has any effect on pulmonary vasculature in nitrofen-induced experimental congenital diaphragmatic hernia (CDH) in a rat model.


METHODS
A CDH model was induced in pregnant rats after administration of 100 mg nitrofen on day 9.5 of gestation. Antenatal dexamethasone, 0.25 mg/kg was given intraperitoneally on day 18.5 and 19.5 of gestation. The fetuses were divided into three groups: group I (n = 10), normal controls; group II (n = 10), nitrofen-induced CDH; group III (n = 10), nitrofen-induced CDH with maternal antenatal dexamethasone treatment. The fetuses were killed by cesarean section at term. Victorian blue van Gieson staining and immunostaining with antialpha smooth muscle actin (ASMA) were performed on lung tissue. The degree of adventitial thickness and area, and medial thickness and area were measured in pulmonary arteries by image analyzer and analyzed statistically.


RESULTS
There was a significant increase in adventitial thickness and area in group II compared with group I and III (P < .01). There was also a significant increase in medial thickness in group II compared with group I and III (P < .01). The degree of adventitial thickness and area and degree of medial thickness and area were similar in controls and maternal dexamethasone-treated CDH group.


CONCLUSIONS
This study demonstrates that antenatal maternal dexamethasone treatment prevents pulmonary artery structural changes in nitrofen-induced CDH in rats.
Taira
Y
Y
Children's Research Centre, Our Lady's Hospital for Sick Children, Dublin, Ireland.
Miyazaki
E
E
Ohshiro
K
K
Yamataka
T
T
Puri
P
P
D000818:Animals; D003907:Dexamethasone / Q000627:therapeutic use*; D004195:Disease Models, Animal; D005260:Female; D005315:Fetal Diseases / Q000139:chemically induced; D005938:Glucocorticoids / Q000627:therapeutic use*; D006548:Hernia, Diaphragmatic / Q000139:chemically induced / Q000150:complications; D065630:Hernias, Diaphragmatic, Congenital; D007091:Image Processing, Computer-Assisted; D007150:Immunohistochemistry; D010647:Phenyl Ethers / Q000008:administration & dosage; D011247:Pregnancy; D011651:Pulmonary Artery / Q000187:drug effects* / Q000196:embryology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D018709:Statistics, Nonparametric
D005938:Glucocorticoids; D010647:Phenyl Ethers; D003907:Dexamethasone; C007350:nitrofen