Evaluation of pressure-driven captive bubble surfactometer.
We modified the captive bubble surfactometer [S. Schürch et al. J. Appl. Physiol. 67: 2389-2396, 1989] to facilitate the measurement of surface adsorption rates and to simplify its construction. We used a range of standards and monolayers of dipalmitoylphosphatidylcholine to check the calibration of the device against measurements made in a Wilhelmy surface balance and in the captive bubble by using a cathetometer, and we found good agreement. As a further test we measured the surface properties of rabbit lavage lung surfactant (60,000 x average g for 60 min) at 1.0 mg phospholipid/ml. This material adsorbed within 1 s to near-equilibrium surface tension, reached surface tensions of < 5 mN/m on the second compression, and formed very stable films. We conclude that a captive bubble surfactometer can provide accurate information about important surface properties of lung surfactant films.
Putz
G
G
Cardiovascular Research Institute, University of California, San Francisco 94143.
Goerke
J
J
Schürch
S
S
Clements
J A
JA
D015060:1,2-Dipalmitoylphosphatidylcholine; D000327:Adsorption; D000818:Animals; D007091:Image Processing, Computer-Assisted; D007202:Indicators and Reagents; D007700:Kinetics; D011312:Pressure; D011663:Pulmonary Surfactants / Q000302:isolation & purification / Q000494:pharmacology*; D011817:Rabbits; D013500:Surface Tension; D007507:Therapeutic Irrigation; D013816:Thermodynamics
D007202:Indicators and Reagents; D011663:Pulmonary Surfactants; D015060:1,2-Dipalmitoylphosphatidylcholine