Mineral Surface-Specific Differences in the Adsorption and Enzymatic Removal of Surfactant and Their Correlation with Cytotoxicity.
Wallace-WE; Keane-MJ; Mike-PS; Hill-CA; Vallyathan-V
Effects of Mineral Dusts on Cells, NATO ASI Series, Vol. H30 1989 :49-56
Data on the cell free in-vitro phospholipase-A2 (PLA2) enzymatic digestion of dipalmitoyl-lecithin (DPL) adsorbed on a quartz (14808607) and a kaolin (1332587) respirable sized dust was presented. The purpose was to investigate mineral specific differences in digestion rates and restoration of dust membranolytic potential. Incubation of these dusts with increasing amounts of dipalmitoyl-lecithin resulted in neutralization of hemolytic potential between 15 and 20 milligrams (mg) DPL adsorbed per gram quartz, and between 75 and 85mg DPL per gram kaolin. Data indicated that a significant amount of the lysolecithin produced remains adsorbed on both dusts after 2 hours, and on quartz at 20 hours. Digestive removal of DPL when the specific activity applied to quartz was decreased to 0.082 units PLA2 per micromole adsorbed DPL, and when the specific activity applied to kaolin was increased to 2.9 units PLA2 per micromole kaolin was demonstrated. The authors conclude that the amount of DPL needed to fully suppress the dusts' hemolytic potentials was similar to that retained on the dusts after mild saline rinsing.
NIOSH-Author; Surfactants; In-vitro-study; Enzyme-activity; Silica-dusts; Metabolic-study; Respiratory-irritants;
Effects of Mineral Dusts on Cells, NATO ASI Series, Vol. H30