| Objects:In this study,bleomycin-induced pulmonary fibrosis in rats as a model to study the TMP on idiopathic pulmonary fibrosis and to explore its mechanism.Methods:80 male SD rats were randomly divided into four groups:normal group,model group,positive control group and TMP group.There were 20 rats in each group.Second day post-surgery,positive control group were fed with sone 21-acetate(1.5mg/kg/d), TMP group were fed with TMP(20mg/kg/d),and control group were treated daily by oral gavage with distilled water.During the experiment,rats with free access to water and food.After they were given the medicine,the rats were killed on 14 and 28 days to get lung tissues for follows measured:weigh rats and lung tissues to comparison of rats weight and lung codfficient;application of biochemical kits detect the expression of SOD,GSH-Px,MDA and iNOS in rats lung tissues;make the paraffin section of rats lung tissues for HE staining and Mallroy staining;make the frozen section of rats lung tissues for Immunohistochemistry studies of caspase-3 and in situ hybridization studies of telomerase.Result:1 Results with HE staining under light microscope:14d,bronchus and alveolus of normal group were normal.Fiber hyperplastic focus was increased in model group.Consolidation area appeared.Next is positive control group in which consolidation area appeared around part of bronchiole.After 14d TMP groups and positive control group showed various degrees fibrosis focus.28d,bronchus and alveolus of normal group were normal.Fibrosis of model group in alveolus interval and around bronchia was more obviously.Fiber hyperplastic focuses were observed lying around alveolus interval and bronchiole.The condition of positive control group was better.Fibrosis degree was not too high in alveolus interval.Fibrosis focus stillappeared around bronchus.Inflammatory cells scattered in some alveolus and bronchiole.TMP group became more distinctly.Fiber hyperplastic focus was less in alveolus interval and there weren't inflammatory cells in alveolus.Fibrosis degree was obviously lower than that of model group and positive control group.TMP group were more effective because few little fibrosis focus remained and structure of alveolus was restored closely to regular comparison group.The results showed TMP had clear curative effect to IPF by reducing fiber piling and restraining forming of fibrosis.2 Mallory staining results:14d,28d,the normal group only in bronchial and alveolar septa around the presence of small amounts of collagen fibers.14d,the thickening of alveolar septum,trachea around the proliferation of collagen fibers were blue in the model group.TMP group the alveolar septum,only a small amount of collagen fibers surrounding the trachea proliferation. The collagen content of positive control group between the model group and TMP group.28d,the interval between,alveolar walls,bronchi and trachea wall were a large number of blue collagen fibers hyperplasia in the model group.Positive control group thickened alveolar septa and peribronchial collagen content is higher.TMP group with low fibrosis,collagen content is less,only a small amount of collagen around the part of the trachea.3 Biochemical determination results:compared with normal group,model group in thelung tissue SOD and GSH-Px activity decreased,MDA levels were significantly increased.Compared with model group,TMP can regulate pulmonary fibrosis free radical metabolism of rats,increased rats SOD and GSH-Px activity,decreased MDA levels.Model group lung tissue iNOS activity than the normal group,the treatment of pulmonary fibrosis in rats with TMP.The rats lung tissue iNOS activity decreased to some extent.14d and 28d in which the model group,compared with a statistically significant,while the TMP group compared to 14d and 28d,also statistically significant.4 caspase-3 immunohistochemical staining results:Normal lung tissue expression of caspase-3 almost.Model group 14d,28d tracheal epithelial cells were found a strong positive expression,some also expressed in alveolar epithelium.Positive control group and TMP group 14d,28d tracheal epithelial cells also appeared positive,but the TMP group 28d tracheal epithelial cells showed weak positive expression.5 Telomerase TERT staining in situ hybridization:normal group,expression of telomerase TERT were a small amount around the trachea,almost no expression in other parts.Model group,14d,28d around the trachea were strong expression emerged, some also expressed in alveolar epithelium.Positive control group and TMP group 14d, 28d also appeared around the tracheal expression,but around the TMP group 28d weakly positive expression of the trachea.Conclusion:1 TMP can adjust the level of pulmonary fibrosis in rats free radicals,reduce free radical oxidative damage to lung tissue structure,and played with idiopathic pulmonary fibrosis in rats.2 TMP can reduce pulmonary fibrosis rats the lung tissue expression of caspase-3,which may be related to reduce alveolar epithelial cell apoptosis.3 TMP can inhibit telomerase activity in lung tissue expression of TERT mRNA,and thus play a prevention of idiopathic pulmonary fibrosis.
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