Intra-amniotic endotoxin accelerates lung maturation in fetal rabbits.
The hypothesis that endotoxin in amniotic fluid accelerates fetal lung maturation was tested. On day 25 of gestation, LPS (5 microg/fetus) was injected intra-amniotically into one uterine horn of eight New Zealand white rabbits, whereas the contralateral amniotic sacs were injected with saline vehicle. The fetuses were delivered 48 h after LPS administration and their lungs were studied. One dam went into premature labor prior to the 48 h time point and was excluded from the study. Mean white cell counts in amniotic fluid and bronchoalveolar lavage fluid from LPS-treated fetuses were increased 3.2-fold (p = 0.04) and 9.9-fold (p = 0.04), respectively. Fetal weights and lung weights were not affected by LPS. Surfactant protein SP-A and SP-B mRNA expressions in LPS-treated fetuses were increased 2.3-fold (p = 0.03) and 1.4-fold (p = 0.04), respectively. Static lung compliance was increased in animals treated with LPS (p = 0.001). Lungs from LPS-treated animals had better aeration than those of controls. Mean volume of inflation-fixed lungs of LPS-treated fetuses was 1.7 times greater than that of controls (p = 0.03).


CONCLUSIONS
Intra-uterine exposure to LPS increases surfactant protein expression and improves lung stability and aeration in preterm animals.
Bry
K
K
Divisions of Neonatology and Pulmonary Biology, Children's Hospital Medical Center, Cincinnati, OH 45229, USA. kristina.bry@chmcc.org
Lappalainen
U
U
D000818:Animals; D015152:Blotting, Northern; D004731:Endotoxins / Q000494:pharmacology*; D005260:Female; D005325:Fetal Organ Maturity / Q000187:drug effects; D006023:Glycoproteins / Q000378:metabolism*; D008070:Lipopolysaccharides; D008168:Lung / Q000187:drug effects / Q000196:embryology* / Q000473:pathology; D011510:Proteolipids / Q000378:metabolism; D037662:Pulmonary Surfactant-Associated Protein A; D037661:Pulmonary Surfactant-Associated Proteins; D011663:Pulmonary Surfactants / Q000378:metabolism*; D011817:Rabbits
D004731:Endotoxins; D006023:Glycoproteins; D008070:Lipopolysaccharides; D011510:Proteolipids; D037662:Pulmonary Surfactant-Associated Protein A; D037661:Pulmonary Surfactant-Associated Proteins; D011663:Pulmonary Surfactants