辐射损伤后不同阶段细胞内外抗氧化酶活性和丙二醛含量变化的研究

Changes in the antioxidase and maleic dialdehyde inside and outside of cells at different injury stage after irradiation

目的观察不同辐射损伤阶段细胞内外SOD、GSH—PX、CAT和MDA的改变。方法36只SD大鼠分为正常对照组和模型组。模型组大鼠采用^60Coγ射线照射0．4、0．8、1．6、3．2、6．4Gy诱导辐射损伤模型。受照后1和21d对大鼠血清和肝细胞内SOD、GSH—PX、CAT活性和MDA含量进行检测。结果与对照组比较，照射后1d细胞内外SOD、GSH．PX、CAT活性明显降低和MDA含量明显增高．其变化幅度与受照剂量有关。照射后21d，0．4～0．8Gy组与照射后1d比较，细胞内外SOD、GSH—PX、CAT活性和MDA含量明显恢复，接近正常对照组水平。但受照剂量超过1．6Gy组抗氧化酶活性和MDA含量与正常对照组比较仍在异常水平。受照剂量超过3．2Gy的大鼠在照射后7d死亡。结论电离辐射可诱发机体细胞内外抗氧化酶活性损伤，其变化幅度与受照剂量有密切的关系。受照剂量在0．8Gy以下．辐射损伤恢复期抗氧化酶活性和MDA含量可明显改善。

Objective To investigate the changes in superoxide dismutase（SDS）, glutathion peroxidase （GSH-PX）, catalase（CAT） and maleic dialdehyde（MDA） inside and outside of cells at different injury stage after irradiation. Methods The rats were divided into normal control group and model groups. The rats in model groups were irradiated with ^60Co gamma rays （0.4, 0.8, 1.6, 3.2 and 6,4 Gy） and induced radiation injury. The SDS, GSH-PX, CAT and MDA in sera and liver cells were detected at days 1 and 21 after irradiation. Results At day 1 after irradiation, the antioxidase activity of the SDS, GSH-PX, CAT was decreased and the content of MDA increased significantly inside and outside of cells. The range of these changes was related with the doses. At day 21 after irradiation, the antioxidase activity of the SDS, GSH-PX, CAT and the content of MDA returned in 0.4-0.8 Gy groups and approached the level of normal control group. But in over 1.6 Gy groups, these antioxidase activity and MDA were still abnormal compared with the normal group, The rats with doses over 3.2 Gy died at day 7 after irradiation. Conclusions The irradiation can induce the injury of antioxidase activity inside and outside of the cells. The abnormal changes range of antioxidase activity is related with irradiated dosage. As to convalescence after radiation injury, the abnormal changes in antioxidase activity and MDA can be significantly improved in groups of below 0.8 Gy.