Pulmonary dysfunction in neonatal SP-B-deficient mice.
Pulmonary function was assessed in newborn wild-type and homozygous and heterozygous surfactant protein B (SP-B)-deficient mice after birth. SP-B +/+ and SP-B+/- mice became well oxygenated and survived postnatally. Although lung compliance was decreased slightly in the SP-B+/- mice, lung volumes and compliances were decreased markedly in homozygous SP-B-/- mice. They died rapidly after birth, failing to inflate their lungs or oxygenate. SP-B proprotein was absent in the SP-B-/- mice and was reduced in the SP-B+/- mice, as assessed by Western analysis. Surfactant protein A, surfactant proprotein C, surfactant protein D, and surfactant phospholipid content in lungs from SP-B+/- and SP-B-/- mice were not altered. Lung saturated phosphatidylcholine and precursor incorporation into saturated phosphatidylcholine were not influenced by SP-B genotype. Intratracheal administration of perfluorocarbon resulted in lung expansion, oxygenation, and prolonged survival of SP-B-/- mice and in reduced lung compliance in SP-B+/+ and SP-B+/- mice. Lack of SP-B caused respiratory failure at birth, and decreased SP-B protein was associated with reduced lung compliance. These findings demonstrate the critical role of SP-B in perinatal adaptation to air breathing.
Tokieda
K
K
Division of Neonatology, Children's Hospital Medical Center, Cincinnati, Ohio 45229-3039, USA.
Whitsett
J A
JA
Clark
J C
JC
Weaver
T E
TE
Ikeda
K
K
McConnell
K B
KB
Jobe
A H
AH
Ikegami
M
M
Iwamoto
H S
HS
D000818:Animals; D000831:Animals, Newborn; D005466:Fluorocarbons / Q000633:toxicity; D006579:Heterozygote; D006720:Homozygote; D008168:Lung / Q000473:pathology / Q000502:physiology* / Q000503:physiopathology*; D051379:Mice; D018345:Mice, Knockout; D011510:Proteolipids / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism*; D037661:Pulmonary Surfactant-Associated Proteins; D011663:Pulmonary Surfactants / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism*
D005466:Fluorocarbons; D011510:Proteolipids; D037661:Pulmonary Surfactant-Associated Proteins; D011663:Pulmonary Surfactants