Background/alm: Recent studies show that leakage of plasma proteins into the alveolar space may lead to inhibition of pulmonary surfactant (PS) function in vitro. and in vivo. We studied the effects of serum albumin (AB) and fibrinogen (FB) on surface properties and morphology of PS in vitro.

Subjects: Surfactant-TA (Surfacten™, S-TA), AB, and FB

Interventions: We measured the surface adsorption rate (AR), dynamic minimum & maximum surface tension (min-, max-ST) by Pulsating Bubble Surfactometer, and ultrastructures on series of mixtures with varying concentrations of AB or FB and S-TA.

Results: The AB & FB significantly inhibited of the AR & ST- lowering properties of PS due to the increased the STs of AR, min-ST, and max-ST of PS. The characteristic morphology of the S-TA changed from lamellar rod-like micelles with open ends into spherical structures with loss of their open ends.

Conclusions: We concluded that AB & FB significantly altered PS function and its morphology. These findings support the concept that AB& FB- induced PS dysfunction may play an important role in the pathophysiology of adult respiratory distress syndrome, and this adverse effect of AB & FB on PS might be overcome by administration of large doses of exogenous PS.