Study on lung injury and fibrogenic cytokine production induced by coal fly ash in rats

  Objective   To observe the effects of coal fly ash on lung injury and fibrogenic cytokine production in rats and elucidate the pathogenesis of the pneumoconiosis caused by the coal fly ash.

  Methods   The rats were inoculated intratracheally with coal fly ash from a thermal power station.The quartz was used as a positive dust.Controls were similarly inoculated with physiological saline.All the animals were killed 10 days after dust inoculation.The lungs were immediately lavaged.The cell-free supernatant was separated for examining the contents of lactate dehydrogenase(LDH), the total proteins, and the total phospholipid.The lung sections were placed on slides for immunohistochemistry of tumor necrosis factor-α(TNF-α), transforing growth factor-β(TGF-β₁)and transforming growth factor-α(TGF-α).

  Results   Compared with the controls, the contents of LDH, the total proteins and the total phopholipid were significantly elevated by coal fly ash(P < 0.05).The lung of controls showed no TNF-α and TGF-β₁ labeling.The increases of TNF-α and-β₁ expression in the lung tissue of rats were observed in the coal fly ash group(P < 0.05).

  Conclusion   Lung injury and increased production of fibrogenic cytokine TNF-αand TGF2β₁ may play an important role in the pneumoconiosis caused by the coal fly ash.