Dipalmitoyl lecithin and lung surfactant adsorption at an air-liquid interface by respirable particles.
Environ Res 1986 Oct; 41(1):120-129
Possible changes in surface properties of 1,2-dipalmitoyl- phosphatidylcholine (DPL) and lung surfactant induced by kaolin (1332587) dust were investigated using a Wilhelmy surface balance. The effects of fly ash (68131748), which is the solid residue remaining after coal combustion and which is hypothesized to cause a new pneumoconiosis, were also investigated. Since the physiological effects of inhalants are probably determined by the physicochemical properties of the inhaled materials, inorganic dusts of alumina (1344281) and zinc (7440666) with known surface areas were also used to study the effects of specific particle surface area on the DPL film at the air liquid interface. Lung alveolar surfactant (LAS) from male Sprague-Dawley-rats was obtained by lavaging the lungs of anesthetized rats with a total volume of 30 milliliters of saline. Particles were sprinkled onto either DPL or LAS films after the fourth cycle at the minimum surface area. With increasing amounts of kaolin (0.47, 1.47 and 3.23 milligrams (mg)) sprinkled onto the DPL film, the hysteresis of the surface tension surface area decreased; the maximum surface tension remained approximately constant while the minimum surface tension increased. The hysteresis area essentially disappeared when about 4mg of kaolin was added. When foam obtained from rat lung lavage fluid was spread onto the aqueous surface of the Wilhelmy balance, the minimum surface tension was higher and the maximum surface tension was lower than the results obtained with the synthetic DPL. The hysteresis area was larger than that produced by DPT. Kaolin caused the hysteresis area of the lung surfactant to decrease. Results with fly ash were similar to those using kaolin. When 1mg of alumina or zinc-oxide (1314132) was added to the DPL film, minimum surface tensions increased to a higher extent when the particles with larger surface area were used. Hysteresis decreased faster as the surface area per gram of particle increased. The authors conclude that the effects of particulate on synthetic DPL and lung surfactant surface properties can be successfully studied in a simple in-vitro system such as the Wilhelmy balance.
Laboratory-animals; In-vitro-studies; Mineral-dusts; NIOSH-Author; Dust-particles; Lung-irritants; Lung-disorders; Zinc-compounds; Pulmonary-system-disorders; Coal-dust
1332-58-7; 68131-74-8; 1344-28-1; 7440-66-6; 1314-13-2