Wallace W E, Keane M J, Mike P S, Hill C A, Vallyathan V, Regad E D
National Institute for Occupational Safety and Health, Division of Respiratory Disease Studies, Morgantown, West Virginia.
J Toxicol Environ Health. 1992 Nov;37(3):391-409. doi: 10.1080/15287399209531679.
Respirable-sized quartz, a well-established fibrogenic mineral dust, is compared with kaolin in erythrocyte hemolysis assays after treatment with saline dispersion of dipalmitoyl phosphatidylcholine, a primary phospholipid component of pulmonary surfactant. Both dusts are rendered inactive after treatment, but the membranolytic activity is partly to fully restored after treatment with phospholipase A2, an enzyme normally associated with cellular plasma membranes and lysosomes. Phospholipid-coated dusts were incubated for periods of 2-72 h at a series of applied enzyme concentrations, and the adsorbed lipid species and hemolytic activity were quantitated at each time for both dusts. Surfactant was lost more readily from quartz than from kaolin, with consequent more rapid restoration of mineral surface hemolytic activity for quartz. Interactions of surfactant and mineral surface functional groups responsible for the mineral-specific rate differences, and implications for determining the mineral surface bioavailability of silica and silicate dusts, are discussed.
可吸入粒径的石英是一种公认的致纤维化矿物粉尘，在与肺表面活性剂的主要磷脂成分二棕榈酰磷脂酰胆碱的盐水分散液处理后，在红细胞溶血试验中与高岭土进行了比较。两种粉尘在处理后均失去活性，但在用磷脂酶A2处理后，膜溶解活性部分至完全恢复，磷脂酶A2是一种通常与细胞质膜和溶酶体相关的酶。将磷脂包被的粉尘在一系列应用的酶浓度下孵育2至72小时，并在每个时间点对两种粉尘的吸附脂质种类和溶血活性进行定量。与高岭土相比，石英更容易失去表面活性剂，因此石英的矿物表面溶血活性恢复得更快。讨论了表面活性剂与导致矿物特异性速率差异的矿物表面官能团之间的相互作用，以及对确定二氧化硅和硅酸盐粉尘的矿物表面生物利用度的影响。
