每周重复照射建立大鼠放射性肺损伤模型的评价

Evaluation on the Model of Radiation-induced Lung Injury of Rat Caused by Weekly Repeated Radiation

目的评价每周小剂量重复照射大鼠放射性肺损伤模型的可行性、科学性及实用性。方法36只Wistar种雌性大鼠,按5:1比例随机分为照射组(A组)30只、对照组(B组)6只。6-MV直线加速器对A组大鼠右肺进行分次照射(5Gy/次,1次/周,累积剂量最高为30Gy),于照射后第4、6、8、12、26周处死,每时相点处死6只,B组于第4周末处死。观察动物活体外观、肺的大体标本、行HE染色观察大鼠肺组织学变化、ELISA法检测血清和SP法检测肺组织中的TGF-β1蛋白表达。结果A组受照肺组织表现出放射性肺炎及肺纤维化,大鼠血清和肺组织TGF-β1表达第4周表达升高,到第12周达到高峰,26周下降。结论每周小剂量重复照射所制作的大鼠放射性肺损伤模型稳定可靠,动物死亡率低,符合临床放疗实际。

Objective To evaluate the feasibility, rationality and practicability about the model of radiation-induced lung injury of rat caused by weekly repeated low dose radiation. Methods At a ratio of five to one,36 Wistar rats were randomly divided into irradiation group（A group, n = 30） and control group （ B group, n = 6）. A group was irradiated fractionally by 6-kv linear acceleratorat at right hemithorax（5 Gy every time, once a week, highest accumulated dose 30Gy）, six of which were killed on 4rd,6 th,8 th, 12 th and 26th week after radiation. And B group were killed on 4rd week after radiation. Then we observed the living appearance of rats, general sample of radiated lung, histological change of lungs stained with HE, the expression of TGF-β1 of blood serum by ELISA and lung by SP. Results Display of radiating pneumonia and lung fibrosis are observed in radiated lung histology of the A group rats. TGF-β1 level in serum and lung of the A group rats showed an increase from 4th week after the first radiation, reaching the highest level at 12th week, and descending at 26th week. Conclusion The model of radiation-induced lung injury of rat caused by weekly repeated low dose radiation is stable and reliable, has lower death rate, conform with the practise of clinical radiation therapy.