重组人铜锌超氧化物歧化酶对小鼠抗氧化酶和免疫细胞的辐射防护作用

Radioprotective effect of recombinant human CuZn SOD on activities of antioxidases and immunocytes in irradiated mice.

目的探讨重组人铜锌超氧化物歧化酶（ｒｈＣｕＺｎ－ＳＯＤ）的辐射防护作用。方法观察６０Ｃｏγ射线５～７Ｇｙ照射对小鼠体内抗氧化酶和免疫细胞的影响，以及给予ｒｈＣｕＺｎ－ＳＯＤ后的抗放效应。结果与照射对照组比较，ｒｈＣｕＺｎ－ＳＯＤ可明显减轻受照小鼠血液和肝细胞浆中总超氧化物歧化酶（Ｔ－ＳＯＤ）、铜锌超氧化物歧化酶（ＣｕＺｎ－ＳＯＤ）、谷胱甘肽过氧化物酶（ＧＳＨ－Ｐｘ）、过氧化氢酶（ＣＡＴ）的活性下降的程度。ｒｈＣｕＺｎ－ＳＯＤ亦可明显增强受照小鼠脾Ｔ淋巴细胞对刀豆蛋白Ａ的增殖反应和自然杀伤细胞的活性；提高小鼠全脾淋巴细胞、外周血白细胞和相对淋巴细胞计数；以及延长了３０天平均生存时间。不同给药方法中，辐射前后给药组的效果优于辐射前或辐射后给药组。结论抗氧化酶活性的降低和氧自由基作用的增强可能是电离辐射引起机体过氧化损伤，导致组织细胞功能异常的重要原因。ｒｈＣｕＺｎ－ＳＯＤ对小鼠抗氧化酶和免疫细胞以及整体均具有辐射防护作用，可能主要由于其直接清除氧自由基的功能，其次通过这种保护功能也促进其他抗氧化酶发挥了一定的协同作用。

Objective The radioprotective effect of recombinant human CuZn superoxide dismutase (rhCuZnSOD) was investigated. Method The changes of antioxidase and immunocyte activities were observed in mice given rhCuZn SOD before and/or after 5 7 Gyγ irradiation. Results rhCuZn SOD showed significant radioprotective effect on irradiated mice,including accelerating activities of CuZnSOD,glutathione peroxidase (GSH Px) and catalase (CAT) in blood and liver cells ( P <0 01),reducing contents of lipid peroxidase (LPO),enhancing proliferative response of T lymphocytes to Con<A and activity of natural killer cells in spleen ( P <0.05),increasing the numbers of whole spleen lymphocytes,leucocytes and ralative lymphocyte counts in peripheral blood ( P <0 05 0 01),and prolonging average survival time of 30 days. Conclusion Decrease of antioxidase activities and increase of free radicals may be main causes of irradiation induced peroxidation and damage to cell activities.The rhCuZn SOD has radioprotective effect which may be due to its function of eliminating free radicals and the joint action of other antioxidases.