title: Induction of intra- and extra-cellular phospholipids in the lungs of rats exposed to silica.
abstract: Intracellular and extracellular compartments of phospholipids in the lungs of rats were examined 28 days after intratracheal injection of silica (200 mg/kg). All compartments containing phospholipids were elevated, but the largest increases were seen in the intracellular and extracellular pulmonary surfactant. Intracellular pulmonary surfactant increased 123-fold from 1.18 +/- 0.65 to 144.9 +/- 53.8 and the extracellular surfactant increased 22-fold from 1.17 +/- 0.04 to 25.1 +/- 7.1 mg per pair of rat lungs respectively. The phospholipid composition of intracellular and extracellular surfactant did not change in response to silica, except for an almost 2-fold increase in the percentage of total phosphatidylinositol in both compartments. The phospholipid content of the lungs increased from 24.9 +/- 4.6 to 268.6 +/- 20.8 mg, with the intracellular and extracellular surfactant accounting for 59.1 and 24.6% of this total increase respectively. These data demonstrate that the major increases in the phospholipid content of the lungs induced by silica is associated with the pulmonary-surfactant system.
mesh_terms: D000818:Animals; D004247:DNA / Q000378:metabolism; D005110:Extracellular Space / Q000187:drug effects / Q000378:metabolism; D007424:Intracellular Fluid / Q000187:drug effects / Q000378:metabolism; D008168:Lung / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D009929:Organ Size / Q000187:drug effects; D010743:Phospholipids / Q000378:metabolism*; D011506:Proteins / Q000378:metabolism; D011663:Pulmonary Surfactants / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D012822:Silicon Dioxide / Q000494:pharmacology*; D014018:Tissue Distribution
chemical_list: D010743:Phospholipids; D011506:Proteins; D011663:Pulmonary Surfactants; D012822:Silicon Dioxide; D004247:DNA