低剂量辐射对小鼠胸腺细胞浆和细胞核蛋白质表达的影响

目的　研究低剂量电离辐射对昆明小鼠胸腺细胞浆和细胞核蛋白质表达的影响。方法　在分离 75mGy照射组和假照射组小鼠胸腺细胞浆和细胞核的基础上 ,采用SephadexG 10 0凝胶过滤和高效液相分析两组小鼠胸腺细胞蛋白质的表达 ,通过小鼠脾淋巴细胞转化和人外周血淋巴细胞染色体畸变检测这些蛋白质表达的生物活性。结果　胸腺细胞浆相对分子质量为 6 1 4× 10 3的蛋白质和胸腺细胞核相对分子质量 30 4× 10 3的蛋白质照射组比假照射组明显增加。并且这些增加的蛋白质组分对ConA刺激正常小鼠脾淋巴细胞转化和X射线损伤人外周血淋巴细胞所致染色体畸变具有刺激和保护作用。结论　低剂量辐射兴奋效应可能与胸腺细胞浆 6 1 4× 10 3的蛋白质和胸腺细胞核 30 4× 10 3的蛋白质表达增高有关。

Effect of low dose radiation on thymocyte cytosol and nuclei protein synthesis in mice

Objective\ To the effect of low dose radiation on thymocyte cytosol and nuclei protein synthesis in mice. Methods\ The expression of proteins was analyzed by gel filtration with Sephadex G\|100 and HPLC based on separation of proteins on thymocyte cytosol and nuclei after whole\|body irradiation with 75 mGy X\|rays and sham\|irradiation,and their biological activity was examined by mouse splenocyte proliferation and chromosome aberration of human peripheral blood lymphocytes. Results\ HPLC analysis showed that there was a marked increase in expression of 61 4 kD protein in the extract of thymocyte cytosol and 30 4 kD protein in the extract of thymocyte nuclei in comparison with the corresponding fractions from the sham\|irradiated control mice.These protein fractions from the thymocyte cytosol and nuclei of the irradiated mice showed both stimulating effect on normal T cell proliferation and protective effect on chromosome damage induced by high dose radiation. Conclusion\ These findings might have implications in study of mechanism of immunoenhancement and cytogenetic adaptive response induced by low dose radiation.