ABSTRACT
I. Basic Considerations 302
A. Function and Composition of Pulmonary Surfactant 302
B. Surface Activity of PS 303
C. Adsorption of Phospholipids 304
D. Compression of Phospholipids 305
II. The Role of SP-C for the Structure-Function
Relationship of PS 306
A. Methods 306
B. Vesicle Adsorption 308
C. Film Formation 308
D. Equilibrium Structure 311
E. Expansion and Compression 313
Acknowledgments 314
References 314
I. Basic Considerations
A. Function and Composition of Pulmonary Surfactant
The molecular film of pulmonary surfactant (PS) offsets the surface tensions of
the hydrated lung epithelia to the air and thereby provides stability to the lung.
In a condition of a dysfunctional surfactant, on the other hand, the surface
tension will be high throughout the lung. As a consequence, the alveoli will
merge with the small airways. As a result, gas exchange area is lost and lung
injury may occur. In addition to providing stability to the lung, the reduction
in surface tension reduces the work of breathing. The work required to inflate
the lung upon inspiration is proportional to the actual surface tension of the inter-
face and, hence, strongly reduced by the interfacial film.
