富勒醇对贻贝棘尾虫的辐射防护机制  

Radioprotection mechanisms of fullerenol for stylonychia mytilus

作　　者：赵群芬[1] 诸颖[1] 李宇国[1] 刘瑞丽[1] 徐晶莹[1] 李晴暖[1] 李文新[1] 

机构地区：[1]中国科学院上海应用物理研究所核分析开放实验室

出　　处：《辐射研究与辐射工艺学报》2005年第5期296-301,共6页Journal of Radiation Research and Radiation Processing

基　　金：中国科学院知识创新工程方向性项目(10475109)资助

摘　　要：为进一步了解富勒醇对贻贝棘尾虫γ辐射防护的机制,在先前工作基础上测定了0.10mgmL-1的富勒醇存在下,剂量为100—2000Gy范围内贻贝棘尾虫辐照后第5d的存活率,并用光学和透射电子显微镜观察了辐照后贻贝棘尾虫形态和超微结构的变化,测定了与自由基相关的酶的活性(超氧化物歧化酶Superoxidedismutase,SOD和过氧化氢酶Catalase,CAT)和脂质过氧化产物(丙二醛Malondialdehyde,MDA和脂褐素Lipotusion,LIP)。结果表明,当剂量为100—1500Gy时,富勒醇能明显提高贻贝棘尾虫γ辐照后的存活率,当剂量达到2000Gy时,富勒醇对存活率无明显影响,表明富勒醇对贻贝棘尾虫γ辐射防护作用不仅和它浓度有关,而且与γ辐射剂量相关。显微镜观察结果在细胞和亚细胞层次揭示了贻贝棘尾虫辐射损伤的结构特征,并给出了富勒醇防护作用的附加证据。未加富勒醇辐照组中SOD和CAT的活性低于对照组(p<0.01),加富勒醇辐照组中SOD和CAT的活性明显高于未加富勒醇辐照组和对照组(p<0.01,p<0.01),而加富勒醇辐照组中MDA和LIP的含量却显著低于对照组(p<0.01,p<0.05)和辐照组(p<0.01),由此推断富勒醇主要通过清除自由基,刺激SOD和CAT的活性,同时减少细胞膜上的脂质过氧化反应,达到对贻贝棘尾虫的辐射防护作用。To have a better understanding on radioprotection mechanisms of fullerenol, surviving fraction was counted for Stylonychia mytilus irradiated by ^60Co γ-rays to 100-2000Gy, with fullerenol of 0.10mg mL^1 being added to some of the sample groups, on the fifth day after the irradiation. Morphologic and superstructure changes were observed with optic microscope and transmission electricity microscope. Superoxide dismutase （SOD）, catalase （CAT）, malondialdehyde （MDA）, and lipofusion （LIP） levels were measured. The results showed that fullerenols could obviously enhance surviving fractions of the Stylonychia mytilus irradiated to up to 1500 Gy. This indicates that the radioprotection is related to both fullerenols concentration and degree of the damages caused by the γ-ray exposure. Microscopic images revealed characteristics of the radiation damages with celluar and subcelluar structures of the Stylonychia mytilus, and these gave additional evidence for radioprotection of fullerenol. The activity of SOD and CAT of the irradiated groups are lower than the control group without irradiation （P〈0.01）. The presence of fullerenol obviously increased SOD and CAT activities of the irradiated group, in comparison to the control groups without fullerenol or without irradiation, with P〈0.01 in both cases. The MDA and LIP levels of the fullerenol-added and irradiated groups lowered significantly than the control groups （P〈0.01, P〈0.05, respectively）. The study shows that fullerenols have a good protection for the Stylonychia mytilus from they-ray exposure. Protective effect of fullerenols on damages induced by γ-rays seems to be mediated, at least in part, through their antioxidantive and radical scavenger activities.

关 键 词：富勒醇 辐射防护 贻贝棘尾虫 自由基 

分 类 号：Q691.9[生物学—生物物理学] Q937