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.
Divisions of Neonatology and Pulmonary Biology, Children's Hospital Medical Center, Cincinnati, OH 45229, USA. kristina.bry@chmcc.org
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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