Protective effect of ulinastatin on inhalation lung injury caused by black gunpowder smoke in rats and its inhibitory effect on the mRNA expression of IL-1β and TNF-α

Objectives 　To explore the protective effect of ulinastatin (UTI) on inhalation lung injury caused by black gunpowder smoke in rats and its inhibitory effect on the mRNA expression of interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α). Methods 　Thirty healthy male Wistar rats were randomly divided into 5 groups (n=6): normal control group (C), inhalation lung injury group (I), high-dose UTI group (UH), medium-dose UTI group (UM) and low-dose UTI group (UL). The rat model of inhalation lung injury was reproduced by a self-made smoke generator. Rats in UH, UM and UL group were given 100 000, 50 000 and 20 000U/(kg.d), respectively, of UTI by intraperitoneal injection. The animals were sacrificed 40h later, then the arterial blood gas values, lung wet-to-dry weight ratio (W/D), white blood cell count and protein concentration in bronchoalveolar lavage fluid (BALF), myeloperoxidase (MPO) activity in serum and lung tissue, and malondialdehyde (MDA) content in lung tissue were determined, and the macroscopic and histological changes in lung tissue were evaluated. The mRNA expression of toll-like receptor 4 (TLR-4), IL-1β and TNF-α were determined by quantitative real-time reverse transcription-PCR (qRT-PCR). Results 　The values of PaO2 in UH, UM and UL group were higher than that in group I (P 0.05). MPO activity in serum and lung tissue and MDA content in UH group were both lower than those in group I (P 0.05). The mRNA expression of TNF-α in UH group was lower than that in group I, the mRNA expression of IL-1β in UH, UM and UL group was lower than that in group I (P 0.05). The mRNA expression level of TLR-4 in each group was similar (P>0.05). Histopathological observation showed less inflammatory exudates and infiltrations in 3 UTI treated groups than in the I group. Conclusion 　UTI shows a protective effect on inhalation lung injury caused by black gunpowder smoke in rats through the mechanism of anti-inflammation and anti-oxidation, and high-dose UTI can effectively inhibit the mRNA expression of IL-1β and TNF-α. DOI: 10.11855/j.issn.0577-7402.2014.03.14