Antenatal administration of granulocyte-macrophage colony-stimulating factor increases fetal lung maturation and endothelial nitric oxide synthase expression in the fetal rat lung.
OBJECTIVE
We investigated how maternal administration of granulocyte-macrophage colony-stimulating factor (GM-CSF) induced fetal lung maturation compared with dexamethasone and whether maternal administration of GM-CSF and dexamethasone influenced the fetal lung eNOS expression.


METHODS
Thirty pregnant rats were divided into three groups of 10 rats each to receive GM-CSF, dexamethasone or saline solution at 16 days of gestation. Lung maturation using bronchial area and immunohistochemical lung airway epithelium and the vascular endothelial eNOS expression, using H Scores, were evaluated at 18 and 20 days of gestation. The statistical analysis was done with the Kruskal-Wallis test for comparisons of more than two groups and the Mann-Whitney U-test as a post hoc test using SPSS for windows release 10.0. Values of p>0, 0.05 were considered significant.


RESULTS
On the 20th day of gestation both GM-CSF and dexamethasone injections caused a significant increase in fetal lung bronchial area, as compared with the controls (24.9%, 36.8%, 13.4%, respectively, p=0.001). eNOS immunoreactivity was observed in the endothelium of large pulmonary vessels and large and small airway epithelium on the 18th and 20th day of gestation. Maternal GM-CSF and dexamethasone increased lung eNOS expression in the airway epithelium when compared to controls.


CONCLUSIONS
Maternal administration of GM-CSF induced fetal lung maturation and this effect may be mediated, at least partly, by an increase in the eNOS expression.
Baytur
Yesim Bulbul
YB
Department of Obstetrics and Gynecology, Celal Bayar University School of Medicine, Manisa, Turkey.
Ozbilgin
Kemal
K
Yuksel
Hasan
H
Kose
Can
C
D000818:Animals; D003907:Dexamethasone / Q000008:administration & dosage; D005260:Female; D005325:Fetal Organ Maturity / Q000187:drug effects*; D005938:Glucocorticoids / Q000008:administration & dosage; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000008:administration & dosage*; D007150:Immunohistochemistry; D008168:Lung / Q000196:embryology* / Q000201:enzymology*; D008431:Maternal-Fetal Exchange; D052250:Nitric Oxide Synthase Type III / Q000378:metabolism*; D011247:Pregnancy; D051381:Rats; D017208:Rats, Wistar
D005938:Glucocorticoids; D003907:Dexamethasone; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D052250:Nitric Oxide Synthase Type III