The role of MMP-2 mRNA in endotoxin-induced acute lung injury in rabbits and the effects of meloxican in its treatment / 解放军医学杂志

ABSTRACT

Objective To investigate the expression of matrix metalloproteinase-2 (MMP-2) mRNA in lungs of rabbits with acute lung injury (ALI) induced by endotoxin (ET) and the effects of meloxicam in its treatment, and to explore the protective mechanism of meloxicam. Methods Twenty four Japanese flap-eared white rabbits were randomly assigned to three groups control group, ET-challenge group and meloxicam-treatment group. There were eight rabbits in each group. ALI model of rabbits was replicated with intravenous ET injection (700?g/kg weight), and meloxicam (2.5mg/kg weight) was intravenously given afber ET challenge in the treatment group. During the experiment, arterial blood gases, lung wet/dry (W/D), lung water content, the pathologic changes in lung, the expressions of MMP-2 mRNA in the lungs were determined. Results Compared with control group, oxygen saturation index (PaO_2/FiO_2) was significantly decreased and pulmonary edema, hemorrhage, extensive inflammatory cells infiltration were observed in ET group. The lung wet/dry (W/D), lung water content and the expressions of MMP-2 mRNA were significantly higher in ET group than those in control group. In meloxicam-treatment group, PaO_2/FiO_2 remained in normal range, and the lung wet/dry (W/D), the lung water content and the expressions of MMP-2 mRNA were significantly lower than those in ET group. The pathologic changes in lung tissues were not severe in group C. Conclusion The up-regulation of MMP-2 mRNA expression was observed in ALI animal model. Meloxicam could down-regulate MMP-2 mRNA expression, producing protective effects on ALI induced by ET in rabbits.