A biophysical mechanism by which plasma proteins inhibit lung surfactant activity

✍ Scribed by B.A. Holm; G. Enhorning; R.H. Notter

• Publisher: Elsevier Science
• Year: 1988
• Tongue: English
• Weight: 489 KB
• Volume: 49
• Category: Article
• ISSN: 0009-3084
• DOI: 10.1016/0009-3084(88)90063-1

✦ Synopsis

These in vitro experiments study a potential mechanism by which plasma proteins, found in the alveoli during pulmonary edema and hemorrhage, may act to inhibit the surface activity of pulmonary surfactant. The results indicate that the inhibition of the adsorption facility and surface tension lowering ability of a calf lung surfactant extract (CLSE) by albumin, hemoglobin, or fibrinogen may he completely abolished by centrifugation of the protein-surfactant mixture at 12,500 xg. Furthermore, albumin, hemoglobin and fibrinogen (1.25 mg/ml) were shown to inhibit the adsorption of high concentrations of CLSE (0.32 mg/ml), normally unaffected by the addition of exogenous proteins, when the CLSE was injected into the subphase under a preformed protein surface film. Similarly, injection of large amounts of these proteins (2.5 mg/ml) into the subphase beneath a preformed CLSE surface film was without effect, even though the CLSE concentration was only 0.06 mg/ml, a surfactant concentration which is normally inhibited by even small amounts of exogenous protein. Taken together, the data suggest that some proteins may inhibit surfactant function by preventing the surfactant phospbolipids from adsorbing to the air-fiquid interface, possibly by a competition between the proteins and CLSE phospbolipids for space at the air-liquid interface rather than direct molecular interactions between proteins and surfactant.