大鼠放射性肺损伤模型的建立与探讨

The establishment and discussion of radioactive lung injury in rats

目的选取建立放射性肺损伤模型的最佳剂量,探讨转化生长因子β1(TGF-β1)和肝细胞生长因子(HGF)在该模型中的表达和意义。方法随机将大鼠分为对照组,照射组A、B、C共四组,射线单次全胸照射,A组剂量12Gy,B组剂量20Gy,C组剂量25Gy。照射后第1、7、14、28和42天终止实验,观察大鼠一般情况、肺组织大体形态及病理学改变,RT-PCR法检测TGF-β1和HGF的表达情况。结果三个照射组在早期主要表现为肺部的急性炎症;晚期可见肺泡间隔增宽以及纤维素样渗出,C组最明显。TGF-β1和HGF在照射组的肺组织中表达有不同程度的增强,与对照组相比差异有统计学意义(P<0.05),C组的升高幅度最明显。结论 25Gy为建立大鼠放射性肺损伤模型的最佳剂量,TGF-β1和HGF与放射性肺损伤的发生、发展有很大的关联,为预测放射性肺损伤的严重程度及其防治奠定实验性的基础。

Objective To find out the best dose of establishing radioactive lung injury model,and discuss the expression and significance of TGF- β1 and HGF in the model. Methods 70 rats were randomly divided into control group,radiation group A,B and C,the rats in radiation groups received single time irradiation at the doses of 12 gy,20 gy and 25 gy respectively. Gave a dynamic observation of the general conditions of rats and the morphological,pathological changes of lung tissues,and the lung tissues were used for the determination of TGF- β1 mRNA and HGF mRNA expression. Results The radiation groups mainly presented acute inflammation of lungs in the early days. After some days alveolar septa became wider and more fibrous protein exudation,group C was the most obvious group. TGF- β1 and HGF expression in the lung tissue of radiation groups had different degrees of enhancement. Compared with control group,the differences were statistically significant（ P〈0.05）. The rise of TGF- β1 and HGF expression in group C was the most obvious ones. Conclusions 25 gy is the most suitable dose to establish radioactive lung injury model. TGF- β1 and HGF has a great relevance to the occurrence and development of radioactive lung injury,lays the experimental foundation for the prediction of severity and the prevention and treatment of radioactive lung injury.