Surfactant phosphatidylcholine metabolism and surfactant function in preterm, ventilated lambs
Preterm lambs were delivered at 138 days gestational age and ventilated for periods up to 24 h in order to study surfactant metabolism and surfactant function. The surfactant-saturated phosphatidylcholine pool in the alveolar wash was 13 +/- 4 mumol/kg and did not change from 10 min to 24 h after birth. Trace amounts of labeled natural sheep surfactant were mixed with fetal lung fluid at birth. By 24 h, 80% of the label had become lung-tissue-associated, yet there was no loss of label from phosphatidylcholine in the lungs when calculated as the sum of the lung tissue plus alveolar wash. De novo synthesized phosphatidylcholine was labeled with choline given by intravascular injection at 1 h of age. Labeled phosphatidylcholine accumulated in the lung tissue linearly to 24 h, and the labeled phosphatidylcholine moved through lamellar body to alveolar pools. The turnover time for alveolar phosphatidylcholine was estimated to be about 13 h, indicating an active metabolic pool. A less surface-active surfactant fraction recovered as a supernatant after centrifugation of the alveolar washes at 40,000 x g increased from birth to 10 min of ventilation, but no subsequent changes in the distribution of surfactant phosphatidylcholine in surfactant fractions occurred. The results were consistent with recycling pathway(s) that maintained surface-active surfactant pools in preterm ventilated lambs.
- OSTI ID:
- 6270976
- Journal Information:
- Am. Rev. Respir. Dis.; (United States), Journal Name: Am. Rev. Respir. Dis.; (United States) Vol. 139:2; ISSN ARDSB
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
59 BASIC BIOLOGICAL SCIENCES
ANIMALS
BIOLOGICAL PATHWAYS
BODY
DOMESTIC ANIMALS
ESTERS
FETUSES
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
LIPIDS
LUNGS
MAMMALS
METABOLISM
ORGANIC COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
ORGANS
PHOSPHOLIPIDS
RESPIRATORY SYSTEM
RUMINANTS
SHEEP
SURFACE PROPERTIES
SURFACE TENSION
SURFACTANTS
TRACER TECHNIQUES
TRITIUM COMPOUNDS
VERTEBRATES