中文摘要：

利用兰州重离子研究装置（HIRFL）提供的高能12C6＋离子束（能量为300 MeV/u,剂量率为0.5Gy/min）辐照大鼠离体胸主动脉环,考察了12C6＋离子束辐照对主动脉环内皮依赖性舒张功能的影响,并采用NBT还原法测定血管环生成超氧阴离子（O 2）水平,加入外源性超氧化物歧化酶（SOD）干预探讨了O 2在内皮功能损伤中的作用。研究结果表明,2.0,4.0和6.0 Gy的12C6＋离子束辐照大鼠胸主动脉环后,可致血管内皮依赖性舒张功能的剂量依赖性明显受损（P〈0.01 vs control group）,并可致血管环NBT还原能力剂量依赖性增加（4.0 Gy时,P〈0.05;6.0 Gy时,P〈0.01 vs control group）。辐照前加入外源性SOD对6.0 Gy12C6＋离子束辐照所致血管环NBT还原能力升高有明显抑制作用（P〈0.01）,对血管环内皮依赖性舒张功能也有明显的保护作用（P〈0.01）,但辐照后10 min加入外源性SOD,其保护作用明显不及前者。结论显示,12C6＋离子束辐照大鼠胸主动脉环可致血管内皮功能受损,O 2清除剂SOD对内皮功能受损有保护作用,说明O 2介导了辐照所致内皮功能损伤。

英文摘要：

Heavy ion beam has many characteristics, and it is expected to be the most suitable radiation therapy technique for malignant tumor. It is lack of depth-understanding on the potential adverse reactions caused by using this technique, because heavy ion radiotherapy is applied to clinical for a short time. Studies have shown that the vascular injury plays a pivotal role in normal tissue damage induced in the conventional radiation therapy, but there was no researchreport on heavy ion beam irradiation-induced vascular injury. In the present study, the isolated aortic rings of rats were irradiated by ^12C^6＋ ion beam （300 MeV/u, 0.5 Gy/min） delivered by HIRFL（Heavy Ion Research Facility in Lanzhou）, the effects of ^12C^6＋ ion beam irradiation on aortic rings with endothelium dependent diastolic function have been investigated. NBT reduction method was used for assaying the vascular ring formation of superoxide anion （OF-） level, and the involvement of superoxide anion in endothelial function injury in rats was investigated through the intervention test of exogenous superoxide dismutase （SOD） on O2·-. The results showed that, the vascular endothelial dependent vasodilation was impaired significantly （P 〈 0.01 vs control group） by irradiation with 2.0, 4.0 and 6.0 Gy ^12C^6＋ ion beam in a dose- dependent manner, and the NBT reduction of vascular rings increased dose-dependently （P 〈0.05 at 4.0 Gy, P 〈0.01 at 6.0 Gy vs control group）. Adding exogenous SOD before irradiation could significantly inhibit the increasing of NBT reduction （P 〈 0.01 ）, and also had protective effect on vascular endothelium dependent diastolic function （P 〈 0.01 ）, but 10 min after irradiation with exogenous SOD, its protective function was significantly less than before. Conclusion indicated that ^12C^6＋ ion beam irradiation could cause endothelial function impaired, O2·- scavenger SOD has a protective effect on endothelial dysfunction, suggesting that O2·- mediates endothelial injury induce