Expression and Effect of MMP-9 and TNF-α in Rats with Phosgene-Induced Acute Lung Injury

Objective:To investigate the role of matrix metalloproteinase-9(MMP-9)and TNF-α in the pathogenesis of acute lung injury induced by phosgene poisoning.Methods: Fifty Sprague Dawley(SD)rats were randomly separated into two groups,the control group and the experiment groups(2h,4h,6h,8h after phosgene poisoning).Sacrifice the experiment rats 2h,4h,6h,8h after phosgene poisoning.Wet and dry ratio of the lung(wet∕dry) and protein concentration,TNF-α and MMP-9 concentration and polymorphonuclear neutrophils in bronchoalveolar lavage fluid(BALF) were recorded,histopathology of the lung was observed under the light scope,and the quantitation of MMP-9mRNA was determined by Real time RT-PCR.Results: Compared to control group,pulmonary edema and inflammatory cells infiltrating appeared in the experiment group rats.Wet-to-dry lung weight ratio,protein concentration,TNF-α concentration and polymorphonuclear neutrophils count in BALF were higher in phosgene poisoning group compared to control group.(P0.05).Acute lung injury caused by phosgene was accompanied with increased expression of MMP-9mRNA in lung tissues(P0.01),which was correlated with lasting of time and aggravation of lung injury.Conclusions: MMP-9 and its relation with inflammatory factors such as TNF-α play an important role in the development of phosgene-induced acute lung injury in rats.