Background: In order to improve biological activity of natural bovine surfactant, we supplemented a commercially available preparation(SF-RIl, Alveofact®) with different lipids resp. proteins.Materials and methods: SF-RIl was supplemented with 11% phosphatidylglycerol (prep.1), 13% sphingomyelin (prep.2), 7.5% phosphatidylethanolamin-plasmalogen (prep.3), 7% phosphoethanolamin (prep.4) and 2% SP-B (prep.5). These surfactants were tested in the rat lung lavage model: animals were tracheotomized and mechanically ventilated (Babylog 1, Drägerwerk AG, FRG) at a rate of 36/minute, 26/6 cm H2O pressure, FiO2 1.0; surfactant depletion was induced by saline lung lavage until paO2 was < 100 mmHg. SF-RIl 100 mg/kg b.w. was given intratracheally and compared with identical doses of the modified surfactant preparations(identical volumes) in 6 animals each with respect to oxygenation.

Results: The table gives an overview:Conclusion: We were able to demonstrate a benefit with respect to biological activity only from supplementation with 13% sphingomyelin.

Table 1
Full size table