Changes in exogenous surfactant in ventilated preterm lamb lungs.
Preterm lambs were treated with either a surfactant from bovine lung (Survanta) or three synthetic surfactants (Exosurf), a 69:22:9 mixture of dipalmitoylphosphatidylcholine, phosphatidylglycerol, and palmitic acid prepared by heat annealing (Lipid Mixture 1) or with glass beads (Lipid Mixture 2). After 5 h of ventilation, large and small aggregate surfactant fractions were isolated from alveolar washes by centrifugation. SP-A was used as an indicator for the association of endogenous surfactant components with the treatment surfactants. The large aggregate fraction from Survanta-treated lambs contained more SP-A than did the fractions from the lambs treated with the other surfactants (p < 0.05). The surfactants used to treat the sheep and the large aggregate surfactants from alveolar washes increased compliances when tested in surfactant-deficient, immature rabbits, relative to that in control animals. The large aggregate fractions in alveolar washes from lambs treated with Survanta, Lipid Mixture 1, and Lipid Mixture 2 improved compliances in the preterm rabbits to a greater extent than did the surfactants used to treat the lambs. The small aggregate fractions were inactive as surfactants. The function of exogenous surfactant can be improved after exposure to the preterm lung. The improvement may result from the association of exogenous surfactant with components of endogenous surfactant.
Ikegami
M
M
Harbor-UCLA Medical Center, UCLA School of Medicine, Department of Pediatrics, Torrance 90502.
Ueda
T
T
Absolom
D
D
Baxter
C
C
Rider
E
E
Jobe
A H
AH
D000704:Analysis of Variance; D000818:Animals; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry; D002417:Cattle; D005260:Female; D005333:Fetus; D006023:Glycoproteins / Q000032:analysis / Q000187:drug effects; D008168:Lung / Q000187:drug effects* / Q000502:physiology; D008297:Male; D011510:Proteolipids / Q000032:analysis / Q000187:drug effects; D037662:Pulmonary Surfactant-Associated Protein A; D037661:Pulmonary Surfactant-Associated Proteins; D011663:Pulmonary Surfactants / Q000032:analysis / Q000187:drug effects / Q000494:pharmacology* / Q000502:physiology; D012121:Respiration, Artificial; D012129:Respiratory Function Tests / Q000706:statistics & numerical data; D012756:Sheep; D013501:Surface-Active Agents / Q000032:analysis / Q000494:pharmacology*; D013997:Time Factors
D006023:Glycoproteins; D011510:Proteolipids; D037662:Pulmonary Surfactant-Associated Protein A; D037661:Pulmonary Surfactant-Associated Proteins; D011663:Pulmonary Surfactants; D013501:Surface-Active Agents