Effects of early treatment with rSP-C surfactant on oxygenation and histology in rats with acute lung injury.

Surfactant treatment in patients with acute respiratory distress syndrome (ARDS) may be a promising treatment strategy. The aim of this study was to investigate whether addition of a recombinant surfactant protein C (rSP-C) to a plain phospholipid (PL) surfactant (PL surfactant) can result in activity comparable to commercially available surfactant preparations (Alveofact and bLES) which contain surfactant protein B and C. In this investigation dose-response comparisons of four surfactants were performed in an animal model of ARDS induced by total lung lavage. The surfactants were given shortly (;10 min) after the last lavage. The effects of surfactant treatment were compared with respect to improve oxygenation and to prevent histopathological changes, such as hyaline membrane formation. The surfactants were compared to lavaged, untreated controls. The surfactants were administered at doses of 25, 50 and 100 mg total amount of phospholipids/kg body weight. At 120 min after early treatment, all three doses of rSP-C surfactant showed statistically significant higher improvements in oxygenation than PL surfactant. This improvement was comparable to bLES and superior to Alveofact. The rSP-C surfactant showed the most prominent effect on preventing hyaline membrane formation. It was again superior to PL surfactant and comparable to bLES. It is concluded that addition of rSP-C enhances the activity of a pure PL surfactant. The rSP-C surfactant showed comparable or even superior activity to bovine-derived surfactant preparations containing both, SP-B and SP-C.