title: A model for the study of the physical behaviour of the lung-surfactant film in vitro.
abstract: A model of the alveolar air-fluid boundary was developed for a future study of the influence of several gases and gas mixtures on the surfactant film of the lung. Since the surface behaviour of the film material changed after denaturation, we had to use it in its native state. It was collected as foam during lung lavage and applied upon a hypophase of concentrated lavage fluid. This combination showed a constant physical behaviour during repeated compression and expansion of its surface. After the excess of applied material had left the surface there was hardly any change of gammamin and gammamax or of the shape of the area versus surface-tension curve (A-gamma curve) during several hours. Mean values of gammamin and gammamax were 5.5 +/- 2.0 and 55.0 +/- 2.0 dyne/cm respectively. The mean value of the hysteresis area was 847 +/- 82 dyne cm. Its shape was similar in all experiments. The stability of this model makes it useful for the intended investigations, but also seems to offer useful data for calculations in relation to the actual behaviour of lung alveolar surfactant in vivo.
mesh_terms: D000818:Animals; D055592:Biophysical Phenomena; D001703:Biophysics; D004285:Dogs; D008954:Models, Biological; D011663:Pulmonary Surfactants / Q000502:physiology*; D013500:Surface Tension
chemical_list: D011663:Pulmonary Surfactants