LONG-TERM EFFECTS OF INSTILLED MINERAL DUSTS ON PULMONARY SURFACTANT ISOLATED FROM MONKEYS

Experiments were carried out to determine the long-term effect of inst illation of 500 mg of generic bituminous, anthracite, quartz, or titan ium dioxide (TiO2) dust on the composition of pulmonary surfactant. Du st was instilled in the caudal lobe of the right lungs of female pigta iled macaque monkeys (Macaca nemestrina). The composition of surfactan t isolated from cell-free bronchoalveolar lavage (CF-BAL) samples obta ined from right lungs (dust exposed) at various times over the followi ng year was compared with that of surfactant isolated from CF-BAL from left lungs (dust free). Little change was seen in the amount of surfa ctant-associated lipid phosphorus as a result of exposure to dust. Exp osure to quartz, anthracite, or TiO2 dust induced a significant increa se in the total amount of protein in the surfactant-enriched fraction. The relative amount of specific proteins was also altered: surfactant -associated protein A decreased, and the amount of the heavy and light chains of immunoglobulin molecules (identified by NH2-terminal amino acid sequence analysis) increased. These changes were visible more tha n a year after instillation of quartz and at least 3 months after inst illation of anthracite dust. Despite variation in the responses of the individual animals, the changes observed might serve as an indicator of the severity of the effect of exposure of the lung to mineral dust and/or to pathogens.