单次剂量照射制备大鼠放射性肝纤维化模型的建立与评价

Establishment and evaluation on the model of radiation-induced liver injury of rat caused by once dose radiation

目的评价单次30 Gy照射制备大鼠放射性肝纤维化模型的可行性、科学性及实用性。方法清洁SD雄性大鼠48只,随机分为照射组(A组)40只、对照组(B组)8只。VARIN 21-EX直线加速器对A组大鼠右肝进行单次照射(30 Gy/次),于照射后第4、8、12、26周处死,每时相点处死8只,B组于第4周末处死。观察大鼠活体外观及肝脏的大体标本,检测大鼠血清中AST、ALT活性,ELISA法测大鼠血清中TGF-β1、HA、PC-Ⅲ、LN含量、HE染色于光镜下观察肝脏组织病理改变、MASSON染色观察大鼠肝脏组织胶原沉积改变;碱水法检测大鼠肝脏组织中Hyp含量,免疫组化法测肝脏组织TGF-β1蛋白表达情况。结果与对照组(B组)比较,A组受照射肝组织表现出放射性肝炎及肝纤维化,照射组大鼠血清中AST,ALT酶活性和TGF-β1水平自第4周明显升高(P<0.05或P<0.01),分别于第8周和第12周达到高峰;照射组大鼠血清中HA、PC-Ⅲ、LN含量和肝脏组织中Hyp含量于照射后第4周显著升高(P<0.05或P<0.01),一直呈上升趋势,照射后26周值最高;照射组大鼠肝脏组织中TGF-β1蛋白表达于照射后第4周也明显升高(P<0.05),照射后第12周达到高峰,第26周开始下降。光镜下可见肝脏病变呈慢性进行性肝纤维化改变。结论单次剂量照射制备的大鼠放射性肝纤维化模型稳定可靠,动物死亡率较低,可以用于实验研究。

Objective To evaluate the feasibility,rationality and practicability about the model of radiation-induced liver injury of rat caused by single 30 Gy dose radiation.Methods 48 SD rats were randomly divided into irradiation group（A group,n=40）and control group（B group,n=8）.A group was irradiated fractionally by VARIN 21-EX linear acceleratorat at right liver（dose 30Gy once）,eight of which were killed on 4rd、8 th 、12 th and 26 th week after radiation.And B group were sacrificed on 4rd weekend.Then we observed the living appearance of rats,general sample of radiated liver.The blood and liver of all rats were collected for further examinations.The level of Hyp in liver tissue and the serum activities of ALT and AST were detected.The level of TGF-β1,HA,PC-Ⅲ and LN of blood serum were measured by ELISA,histological change of livers was observed with hematoxylin-eosin（HE）staining and Masson＇s trichrome staining by optical microscopy.Meanwhile,the expression of TGF-beta1 protein was detected by immunohistochemistry.Results Compared with the control group（B group）,Display of radiating hepatitis and liver fibrosis were observed in radiated liver histology of the A group rats.The activities of AST,ALT and the level of TGF-β1 in serum of the A group rats showed an increase from 4th week after the first radiation（P0.05 or P0.01）,reaching the highest level at 8th and 12th week,respectively.The content of HA,PC-Ⅲ and LN in blood serum and Hyp in liver tissue of the A group rats have significantly increased from 4th week after the first radiation（P0.05 or P0.01）.The expression of TGF-beta1 protein in liver tissue of the A group rats has significantly increased from 4th week（P0.05）.Histological change of livers was chronic progressive liver fibrosis by light microscopy.Conclusion The model of radiation-induced liver injury of rat caused once dose radiation is stable and reliable,has lower death rate,conform to the practice of clinical radiation therapy.