Instillation of chemotactic factor to silica-injected lungs lowers interstitial particle content and reduces pulmonary fibrosis.

摘要: Abstract Silica-induced pulmonary fibrosis usually follows exposure to increased levels of this particulate and its retention in interstitial macrophages the lung. It is suggested that accelerated clearance particles from interstitium may ameliorate subsequent fibrosis. To test hypothesis, one group mice received 2-mg intratracheal (IT) silica; some were phagocytized cleared during inflammatory response, other translocated across epithelium reach by 2 weeks. These later showed fibroblast growth, a doubling lung collagen large silicotic nodules 16 weeks when much silica was still present A second IT silica, then 3 injections N-formyl-L-methionyl-leucyl-phenylalanine (FMLP), leukocyte chemoattractant. Subsequently, significant increase cells seen observed mostly phagocytes within alveolar spaces. Few found at 4 weeks, extensive did not develop weeks; only few small little The results indicate controlled response possible, removal decreases fibrotic response.