高剂量γ射线辐射后大小肠放射敏感性差异研究  

The difference of radiosensitivity between small and large intestines toward high dose of radiation

作　　者：潘燕[1] 华国强 邵春林[1] 

机构地区：[1] 复旦大学放射医学研究所,上海200032 [2] 美国纪念斯隆凯特琳癌症中心

出　　处：《中华放射医学与防护杂志》2015年第6期407-412,共6页Chinese Journal of Radiological Medicine and Protection

基　　金：国家自然科学基金（11179002,81273001,31300692）;国家留学基金委国家公派访问学者项目（留金发[2012]3022）;国家重大科学仪器设备开发专项（2012YQ030142）

摘　　要：目的 探讨高剂量γ射线照射下小鼠大肠、小肠放射敏感性的差异.方法 选取6～8周龄雄性C57 BL/6小鼠,完全随机法分为照射组和健康对照组,照射组接受19 Gy的γ射线全身照射,并于照射后6、12、24、48、72和96 h截取小鼠大肠和小肠,免疫组织化学法检测照射后各时间点大肠小肠及其隐窝干细胞凋亡、增殖的变化,原位杂交法检测大小肠干细胞数目的变化.结果 γ射线照射后,HE染色显示小鼠小肠黏膜受损较大肠更为严重,照后48 h小肠隐窝全部消失,但大肠隐窝增殖指数仍高达0.23（t =4.67,P＜0.05）.与小肠相比,大肠隐窝黏膜上皮细胞在12、24 h凋亡指数显著低于小肠（t=-1.92、-2.42,P＜0.05）.照后12、24 h大肠干细胞凋亡数显著低于小肠（t=-1.98、-2.33,P＜0.05）,照后24、48 h大肠隐窝内干细胞数则显著高于小肠（t=1.98、3.31,P＜0.05）.结论 高剂量辐射条件下,大肠小肠的放射敏感性存在明显差异,而二者干细胞的放射敏感性的差异可能是决定大肠较小肠更为辐射耐受的原因之一.Objective To measure the difference of radiosensitivity between small and large intestines toward high dose of radiation and investigate the role of stem cells in this difference.Methods C57BL/6 male mice,6-8 weeks old,were randomly divided as control group and radiation group received 19 Gy whole body γ-ray irridiation.Large and small intestines of the mice were collected 6,12,24,48,72 and 96 h after radiation.The proliferation and apoptosis of the large and small intestines and their stem cells were then detected by immunochemistry,and the change of stem cell number in the large and small intestines were detected by in-situ hybridization.Results HE staining showed that 19 Gy γ-ray irradiation caused more severe injury in the small intestine,and all the crypt in the small intestine were extinct at 48 h post-radiation.However,the proliferation index of crypt in the large intestine was as high as 0.23 （t =4.67,P 〈0.05）.Compared with the small intestine,the apoptotic index of epithelial cells in the crypt of large intestine was much lower at 12 and 24 h after irradiation （t =-1.92,-2.42,P〈0.05）.The apoptotic population of stem cells in the small intestine at 12 and 24 h post irradiation were significantly lower than that in the large intestine （t =-1.98,-2.33,P 〈 0.05）,and the number of stem cell in the large intestine was significantly higher than that in the small intestine 24,48 h after radiation （t =1.98,3.31,P 〈0.05）.Conclusions The radiosensitivity of small intestine toward high dose of irradiation is significantly higher than that of the large intestine,where the difference in radiosensitivity of stem cells between large intestine and small intestine may be involved.

关 键 词：干细胞 放射敏感性 Γ射线 凋亡 增殖 

分 类 号：R818[医药卫生—放射医学]