虫草菌粉对兔矽肺纤维化早期干预作用

Study on effect of cordyceps sinensis on early-stage silicotic pulmonary fibrosis in rabbits

目的 复制兔矽肺模型,探讨虫草菌粉对兔矽肺纤维化早期干预作用.方法 选取30只健康雄性大耳白兔,随机分为空白对照组、矽肺组、干预组.矽肺组、干预组气管内注入二氧化硅粉尘悬液,空白对照组气管内注入相同体积的生理盐水.兔染矽尘30 d后处死,计算肺脏系数,右肺组织行HE染色,用加碱水解法测定免肺组织的羟脯氨酸含量,实时荧光定量PCR法测免肺组织TGF-β1及Smad7的mRNA表达水平.结果 3组兔肺组织HE染色示,空白对照组正常肺组织,矽肺组、干预组兔肺组织明显纤维化并有矽肺结节形成.矽肺组肺脏系数和Hyp含量高于空白对照组和干预组,差异均有统计学意义（P＜0.05或P＜0.01）.与空白对照组比较,矽肺组和干预组免肺组织TGF-β1表达水平降低,Smad7表达水平升高,差异均有统计学意义（P＜0.02）;与矽肺组比较,干预组免肺组织TGF-β1表达水平下降及Smad7表达水平升高,差异均有统计学意义（P＜0.05）.结论 虫草菌粉可减少矽肺模型兔肺组织TGF-β1 mRNA表达,上调Smad7mRNA,对兔矽肺纤维形成的过程有一定的影响,

Objective To establish a rabbit model of silicotic pulmonary fibrosis and to investigate the effect of cordyceps sinensis in this model.Methods Thirty healthy male white rabbits were randomly divided into control group,silicosis model group,and intervention group.The rabbits in silicosis model group and intervention group received endotracheal perfusion of silicon dioxide suspension （120 mg/kg）,and the control group was treated with the same volume of saline.All the rabbits were sacrificed 30 days later.The lung coefficient was calculated by comparing the lung weight and body weight; the fight lung tissue was stained with hematoxylin-eosin （HE）.The content of hydroxyproline in lung tissue was measured by alkaline hydrolysis.The mRNA levels of transforming growth factor beta 1 （TGF-β1） and mothers against decapentaplegic homolog 7 （Smad7） in rabbit lung sections were determined by real-time PCR.Results No abnormalities were observed by HE staining in the lung tissues of control group,while fibrosis and silicotic nodules were discovered in the silicosis model group and intervention group.The lung coefficient and the content of hydroxyproline in lung tissue were significantly higher in the silicosis model group than in the control group and intervention group （P〈 0.05 or P〈0.01）.Compared with the control group,the silicosis model group and intervention group had significantly increased TGF-β1 mRNA levels but significantly reduced Smad7 mRNA levels （P〈0.02）.Compared with the silicosis model group,the intervention group had a significantly reduced TGF-β1 mRNA level but a significantly increased Smad7 mRNA level （P〈0.05）.Conclusion Cordyceps sinensis is able to reduce the expression of TGF-β1 mRNA and increase the expression of Smad7 mRNA in lung tissues of rabbits with silicotic pulmonary fibrosis,and thus postpone the progression of fibrosis.