Effects of Two Different Surfactants on RBC Membrane and Type II Alveolar Epithelial Cell in Vitro

ABSTRACT

PURPOSE: Respiratory distress syndrome(RDS) is a major cause of death in premature babies. For the treatment of RDS, various artificial pulmonary surfactants have been used. The incidence of pulmonary hemorrhage is increased in association with surfactant therapy in extremely low birth weight infants. But the pathogenesis of this increased incidence is not clear. So we conducted this study to prove whether exposure of RBC or type II alveolar epithelial cell membrane to Surfacten(R) or Exosurf(R) or additive component of Exosurf(R) may lead to increased membrane permeability. METHODS: Washed packed RBC(30microliter) with various concentrations of Surfacten(R), Exosurf(R), hexadecanol and tyroxapol(concentration similar to their content in each Exosurf(R)), were incubated for 2, 24 and 48 hour at 37degrees C. Hemolysis was measured by spectrophotometry. Type II alveolar epithelial cell(HTB-181)(106cell/mL) with 2, 4, 6 and 8mg of Surfacten(R) or Exosurf(R) were incubated for 24 hour at 37degrees C. Lactate dehydrogenase(LDH) release was measured as an indicator of cytotoxicity. RESULTS: RBC hemolysis was increased in a time and dose-dependent manner with both artificial surfactants and additive components of Exosurf(R). This trend, especially, was typically seen in the sample which was incubated for 24 hours, where more hemolysis was seen with Exosurf(R) and tyroxapol than Surfacten(R) and hexadecanol with the above concentration of 2.5mg/2mL(P<0.05). LDH released from type II alveolar epithelial cell with Exosurf(R) was greater than with Surfacten(R), especially at the concentration of 6mg/106cell(P<0.05). CONCLUSION: Artificial surfactant may be associated with in vitro cytotoxicity on RBC membrane and aveolar epithelial cell, and this property was more prominent with Exosurf(R) and the additive components of Exosurf(R), especially with tyroxapol.