1668 surfactant activity following natural surfactant (ns) treatment of premature lambs

ABSTRACT Six 120-day and 6 130-day gestational age lambs were delivered by C-section and supported on ventilators with 100% oxygen. With respiratory failure (pCO2=114±11) the lambs were

treated with 50 mg/kg of 3H labeled NS by tracheal instillation. All the lambs responded dramatically, however the effect was gone within 3 hrs. The specific activity of the 3H labeled

saturated phosphatidyl choline (SPC) in the NS used for treatment had decreased by only 30±4% in the alveolar wash (AW) at sacrifice; thus the treatment dose was minimally diluted. However,

IV injections of 14C-palmitic acid resulted in the appearance of 14C-SPC in sequential samples suctioned from the airways (AS) indicating endogenous synthesis and secretion. Minimum surface

tension (ST) measurements (dynes/cm) made on AS fell from 29±2 to 8±5 after NS and again rose to 32±2 at sacrifice. AW samples taken at sacrifice and containing 1μmole phosphatidylcholine

(PC) did not lower ST below 27±4, while “surfactant” recovered from the AW (R-SA) containing 0.2 μmoles PC lowered ST to <10. (NS containing 0.1 μmoles protein PC will lower ST to

<10). While the phospholipid compositions were similar, the ratio μmole PC/mg protein was 0.13±0.02 in AW, 4±0.4 in R-SA and 5.7±0.6 in NS. Following removal of the R-SA from the AW

samples by centrifugation, the supernatant, when mixed with NS, raised ST from 0 to >30. We demonstrated 1) NS remains in the airways following treatment, and 2) the ability of NS to

lower ST is reversibly inhibited. ARTICLE PDF AUTHOR INFORMATION AUTHORS AND AFFILIATIONS * Department of Pediatrics, UCLA School of Medicine, Harbor-UCLA Medical Center, Torrance Machiko

Ikegami, Alan H Jobe & Theodore H Glatz Authors * Machiko Ikegami View author publications You can also search for this author inPubMed Google Scholar * Alan H Jobe View author

publications You can also search for this author inPubMed Google Scholar * Theodore H Glatz View author publications You can also search for this author inPubMed Google Scholar RIGHTS AND

PERMISSIONS Reprints and permissions ABOUT THIS ARTICLE CITE THIS ARTICLE Ikegami, M., Jobe, A. & Glatz, T. 1668 SURFACTANT ACTIVITY FOLLOWING NATURAL SURFACTANT (NS) TREATMENT OF

PREMATURE LAMBS. _Pediatr Res_ 15 (Suppl 4), 721 (1981). https://doi.org/10.1203/00006450-198104001-01686 Download citation * Issue Date: 01 April 1981 * DOI:

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