电离辐射对小鼠胎脑NO含量及SOD活力的影响

目的探讨孕鼠受γ射线照射后对旁效应器官胎鼠脑组织中NO含量和SOD活力的影响。方法将孕9 d昆明小鼠随机分为7组：空白对照组、0.5 Gy全身照射组、0.5 Gy头部照射组、1.0 Gy全身照射组、1.0 Gy头部照射组、2.0 Gy全身照射组及2.0 Gy头部照射组,照射组用~（60）Co治疗机对小鼠于孕9 d单次急性γ射线垂直照射,于孕18 d取胎鼠脑组织匀浆,测定其NO含量和SOD活性。结果与空白对照组相比,2.0 Gy头部照射组胎脑组织匀浆中NO含量明显增加（P〈0.05）,SOD活力显著下降（P〈0.05）;同时1.0 Gy头部照射组较1.0 Gy全身照射组SOD活力高（P〈0.05）;1.0 Gy头部照射组较1.0 Gy全身照射组NO含量低（P〈0.05）;而2.0 Gy头部照射组较2.0 Gy全身照射组NO含量明显增加（P〈0.05）;1.0 Gy全身照射组、2.0 Gy全身照射组NO含量均明显增加（均P〈0.05）,SOD活力均显著下降（均P〈0.05）。结论孕鼠早期头部受到电离辐射后,诱发体内旁效应,NO自由基增加,SOD活力下降,导致脑组织神经发育损伤,其效应与全身受照时胎脑出现的损伤效应类似。

Effects of Ionizing Radiation on the Content of NO and the Activity of SOD in Fetal Brain Tissue in mice

Objective To observe the changes of the content of NO and the activity of SOD,and to investigate the effect ofγ-rays on fetal brain tissue as bystander effect organ.Methods Pregnant 9d Kunming mice were randomly divided into 7 groups：the blank control group,the 0.5 Gy whole-body exposed group,the 0.5 Gy head-exposed group,the 1.0 Gy whole-body exposed group,the 1.0 Gy head-exposed group,the 2.0 Gy whole body-exposed group and the 2.0 Gy head-exposed group.The exposed mice were exposed with a vertical single acute dose using Co therapy machine when 9d in pregnant,and cesa rean operation were performed to gain fetal mice when 18d in pregnant.Then the content of NO and the activity of SOD were detected using NO and SOD kits.Results Compared with the blank control group, the content of NO in fetal brain in the 2.0 Gy head-exposed group was increased（P〈0.05）,the activity of SOD was decresed.（P〈0.05）;the NO content in the 1.0 Gy head-exposed group was significantly less than that in the 1.0 Gy whole body-exposed group（P〈0.05 ）;the SOD content in the 1.0 Gy head-exposed group was significantly more than that in the 1.0Gy whole body-exposed group（P〈0.05）;while the NO content in the 2.0 Gy head-exposed group was significantly increased than that in the 2.0 Gy whole body-exposed group（P〈0.05）;the content of NO in fetal brain in the 1.0 Gy and the 2.0 Gy whole body-exposed group was increased both（P〈0.05 ）,the activity of SOD was decresed（P〈0.05 ）. Conclusion A large number of NO has produced and SOD activity has decreased in the embryonic brain tissue when the pregnant mice heads are exposed in the early time,it shows that bystander effect in vivo is induced by ionizing radiation,which has a similar effect with that in the whole body-exposed group.