Abstract
ABSTRACT: Surfactant apoprotein A (SP-A) reduces the inhibitory effects of plasma proteins on the surface tension lowering properties of pulmonary surfactant in vitro. To test the effects of SP-A in vivo we administered a complete natural dog lung surfactant (DLS) containing apoproteins SP-A, SP-B, and SP-C, a butanol extract of DLS (DLSE) containing only apoproteins SP-B and SP-C, and DLSE supplemented with SP-A intratracheally to prematurely delivered rabbit pups in the presence of increasing amounts of human plasma. In the absence of plasma DLS and DLSE (100 mg/kg phospholipid) had comparable effects on lung mechanics (compliance during ventilation with a tidal volume of 6–7 mL/kg and quasi-static pressure-volume behavior) in this surfactant deficiency model. Plasma proteins in increasing amounts to a maximum protein concentration of 62.5 mg/mL had no effect on the response of the pups to DLS. In contrast, plasma added to DLSE in concentrations above 20 mg/mL significantly increased the peak inspiratory pressure (PIP) required to ventilate the pups with a tidal volume of 6–7 mL/kg, reduced the calculated total lung compliance, and decreased the deflation lung volumes. The inhibitory effects of plasma on DLSE were significantly less when SP-A was added to DLSE (5:1, phospholipid:SP-A, wt:wt). The addition of SP-A to DLSE in plasma restored the activity of the extract to levels comparable to complete DLS. These results suggest that plasma can interfere with surfactant function and that SP-A has a significant protective effect for surfactant against the inhibitory effects of plasma in vivo.
Similar content being viewed by others
Article PDF
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Yukitake, K., Brown, C., Schlueter, M. et al. Surfactant Apoprotein A Modifies the Inhibitory Effect of Plasma Proteins on Surfactant Activity In Vivo. Pediatr Res 37, 21–25 (1995). https://doi.org/10.1203/00006450-199501000-00005
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1203/00006450-199501000-00005
This article is cited by
-
Morphological alterations of exogenous surfactant inhibited by meconium can be prevented by dextran
Respiratory Research (2006)
-
Surfactant Therapy for Respiratory Distress Syndrome in Premature Neonates
American Journal of Respiratory Medicine (2002)
-
Toxic oxidant species and their impact on the pulmonary surfactant system
Lung (1997)