Objective:To study the changes of transforming growth factor-β1 ( TGF-β1 ) and tumor necrosis factor-α ( TNF-α ) in serum at different stages in the development of rat silicosis model. Methods; Thirty healthy male SD rats were randomly divided into silica exposure group(20 rats) and control group(10 rats). Silica suspension at 40 mg/ml (1 ml) was administrated intratracheally once while equal amount of saline was intratracheal instilled to the rats in control group. Animals were sacrificed at 1st,7th,14th,21th and 28th day after instillation. The levels of TGF-β1 and TNF-a in serum were determined by ELISA. Results; In contrast to control group,TGF-β1 level was decreased at 1st and 7th day(P＜0.01) ,and increased at 14th,21th and 28th day(P＜0.01) in experiment group. And TNF-alevel was increased at 1st, 7th, and 14th day ( P ＜ 0. 01 ) , and decreased at 21th and 28th day ( P ＜ 0. 01 ). Conclusions: Silica can induce the changes of serum TGF-β1 and TNF-α in experimental silicotic rat model. The unusual high expression of TGF-β1 might take part in the pulmonary fibrosis.%目的:研究实验性矽肺大鼠在染尘后不同时期血清转化生长因子-β1(TGF-β1)和肿瘤坏死因子-α(TNF-α)的变化.方法:将30只健康雄性SD大鼠随机分为模型组和对照组,模型组20只,对照组10只.模型组以非暴露方式气管内一次性注入1 ml二氧化硅悬液(40 mg/ml)建立大鼠矽肺模型,对照组气管内注入等量的灭菌生理盐水.分别在染尘后第1、7、14、21、28天各处死4只模型组和2只对照组大鼠,采用酶联免疫吸附(ELISA)法测定血清TGF-β1 和TNF-α的蛋白浓度.结果:模型组TGF-β1 在染尘后第1、7天均显著低于对照组(P<0.01),而第14～28天均显著高于对照组(P<0.01).模型组TNF-α在染矽尘后第1～14天均显著高于对照组(P<0.01),而在第21、28天均显著低于对照组(P<0.01).结论:矽尘可导致血清TGF-β1 和TNF-α的变化,TGF-β1的异常表达可能参与了矽肺肺纤维化的发生和发展.
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