Idiopathic pulmonary fibrosis is divided into chronic progression stage and acute exacerbation stage according to progression of disease;early,middle and late stage according to onset time and clinic symptoms.It is considered that the etiological factors of idiopathic pulmonary fibrosis are repeated suffering of exogenous pathogen,environmental pathogen, deficiency of lung and kidney.The basic pathological products are blood stasis and phlegm turbid,the key point of pathopoiesis is that phlegm and stasis hides deeply and stagnated,the pulmonary collaterals are blocked.In addition,the evolutions of pathogenesis during its different stage are discussed.

Objective To investigate the effects of sivelestat sodium on early inflammatory reaction in rats with smoke inhalation injury. Methods Forty SPF male SD rats were randomly divided into 5 groups:normal control group (A), injury group (B), smoke inhalation treated with 10 mg/kg sivelestat sodium group (C), smoke inhalation treated with 20 mg/kg sivelestat sodium group (D) and smoke inhalation treated with 30 mg/kg sivelestat sodium group (E), 8 rats for each group. After smoke inhalation injury model was established, the treatment groups were intraperitoneally injected sivelestat sodium 10 mg/kg, 20 mg/kg and 30 mg/kg separately. B group was treated with the same volume of physiological saline. After 24 hours,ELISA was used for detecting serum contents of neutrophil elastase (NE), myeloperoxidase (MPO), tumor necrosis factor-α(TNF-α) and interleukin-6 (IL-6) in five groups. Meanwhile the water content of lung tissue was measured, and the pathological changes were observed by HE staining. The thickness of alveolar septum was measured and compared between groups. Results Compared with control group, the serum levels of NE, MPO, IL-6, TNF-α, water content of the lung tissue and thickness of alveolar septum were significantly higher in other four groups (P<0.05). Compared with injury group, the serum levels of NE, MPO, IL-6, TNF-α, water content of the lung tissue and thickness of alveolar septum were significantly lower in treatment groups (P<0.05). Compared with 20 mg/kg treatment group and 30 mg/kg treatment group, the serum levels of NE, MPO, IL-6, TNF-α, water content of the lung tissue and thickness of alveolar septum were significantly lower in 10 mg/kg treatment group (P<0.05). Conclusion The result shows that sivelestat sodium can reduce the early inflammatory reaction of rats with smoke inhalation injury and attenuates the lung edema. In this experiment, the treatment effect of 10 mg/kg sivelestat sodium is better than other treatment doses.