小剂量辐射诱导小鼠免疫细胞早期蛋白质合成动力学变化

DYNAMIC CHANGES OF THE EARLY PROTEIN SYNTHESIS IN MURINE IMMUNE CELLS AFTER LOW DOSE RADIATION

采用３ＨＬｅｕ掺入示踪观察７５ｍＧｙＸ射线全身照射对小鼠免疫细胞蛋白质早期合成的影响。结果表明，小剂量Ｘ射线全身照射后小鼠胸腺细胞蛋白质合成开始增加，６～８ｈ达到峰值，随后逐渐下降。ＳＤＳＰＡＧＥ及光密度扫描结果表明，照射后小鼠胸腺及脾细胞蛋白质合成增加，同一细胞中不同分子量的蛋白质各有其消长特点，不同细胞间合成增加的蛋白质分子量有所不同。这些早期变化的蛋白分子参与复杂的细胞功能调节，可能与辐射兴奋效应有关。

It was shown that there was a marked increase in protein synthesis of thymocytes that were metabolically labelled with 3HLeu for 4, 6, 8 and 12 hous in 1ow dose irradiated mice showing 3326%, 5148%, 5154% and 3498% increase respectively at different time intervals of incubation when the thymic and splenic cells were sampled 4 hours after whole body irradiation (WBI) with 75 mGy Xrays The results suggest that there is an increase in protein synthesis with its peak at 6～8 hours after radiation Changes in protein synthesis of immune cells in mice 4 hours after radiation and incubated for 4～12 h were observed with SDSPAGE followed by densitometrical scanning It is revealed that 28 kD protein synthesis was increased gradually within 12 hours of incubation and 43 kD protein synthesis was increased in the thymocytes rapidly reaching a maximum 2 hours after incubation It was also exhibited that the synthesis of 43 kD protein and 32 kD protein was increased in the splenocytes 2 hours after incubation These findings may have implications in the mechanism of immunoenhancement and adaptive response induced by low dose radiation