STUDY ON EXPRESSION OF MATRIX METALLOPROTEINASE-2 AND MATRIX METALLOPROTEINASE-9 IN LUNG TISSUES OF RATS OF ACUATE PARAQUAT POISONING

[Objective]To investigate the changes of expression of matrix metalloproteinase in lung tissues of rats with acute paraquat(PQ)poisoning.[Methods]A total of 50 SD rats were randomly divided into control group and poisoned group.Intra-gastric administrations with PQ in dose of 50 mg/kg or normal saline solution in the same dose were given the poisoned group and the control group respectively.On the days of 1,3,7,14 and 28 after exposure,the expressions of MMP-2 and MMP-2mRNA,MMP-9 and MMP-9mRNA in lung tissues were evaluated by RT-PCR.[Results]① The expressions of both MMP-2 and MMP-9 in fibroblasts increased on the first day after poisioning and reached the peak on the seventh day.And the expression of MMP-2 was 3.187 times as many as that of the control group(t = 23.667,P﹤0.001),while the expression of MMP-9 was 3.503 times as many as that of the control group(t = 11.399,P﹤0.001).② The expressions of MMP-2mRNA and MMP-9mRNA were enhanced in fibroblasts at 24 h after poisioning.[Conclusions]The expressions of MMP-2 and MMP-9 in fibroblasts are up-regulated in pulmonary interstitial fibrosis model.