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采用凝胶电泳移动变化分析（ＥＭＳＡ）方法，观察了 Ｘ射线全身照射后小鼠胸腺细胞及脾细胞内 ＮＦ－ｋＢ ＤＮＡ结合活性的时程变化及其剂量效应关系。结果表明；胸腺细胞及脾细胞核蛋白提取物内存在两种与 ｋＢ位点特异结合的 ＮＦ－ｋＢ二聚体。 照射后两者的变化时程及剂量效应关系显然不同． ２Ｇｙ照射后胸腺细胞内 ｐ５０／ｐ６５的 ＤＮＡ结合活住在 ２４～４８ｈ稍有升高，而 ｐ５０／ｐ５０的 ＤＮＡ结合活性在照射后很快开始上升，于 ４ｈ达峰值，维持于高水平至 １２ｈ后逐渐下降。 照射后 １２ｈ电离辐射诱导 ｐ５０／ｐ６５复合物活性变化不明显，当剂量达 １Ｇｙ以上时ｐ５０／ｐ５０的ＤＮＡ结合活性呈剂量依赖性升高。提示，中等以上剂量的电离辐射主要诱导具有转导抑制作用的复合物．对脾细胞核蛋白提取物剂量效应关系及２Ｇｙ照射后的时程研究表明，较低剂量辐射对 ｐ５０／ｐ６５ 二聚体的表达有轻度刺激作用，较高剂量则显示抑制效应，而对 ｐ５０／ｐ５０二聚体的活住几乎无影响．提示，ＮＦ－ｋＢ在不同免疫器官内的构成及其对电离辐射的反应存在着差异。
The time-course changes of NF-κB DNA binding activity in mouse thymocytes and splenocytes after X-ray irradiation were observed by EMSA. The dose-response relationship was also observed. The results show that there are two NF-κB dimers that specifically bind to kB sites in the thymus and splenocyte nuclear protein extracts. After irradiation, the time course and dose-response relationship between the two obviously different. The DNA binding activity of p50 / p65 in thymocytes after 2Gy irradiation increased slightly from 24 to 48 hours, and the DNA binding activity of p50 / p50 began to increase rapidly after irradiation, reaching its peak at 4h and maintained at a high level until 12h After gradual decline. The change of p50 / p65 complex induced by ionizing radiation was insignificant at 12h after irradiation, and the DNA binding activity of p50 / p50 was increased in a dose-dependent manner when the dose was over 1Gy. It is suggested that ionizing radiation at medium dose and above mainly induces a complex with transduction inhibition. Dose-effect relationship of splenocyte nuclear protein extracts and time course after 2Gy irradiation showed that lower doses of radiation had a mild stimulating effect on the expression of p50 / p65 dimer, higher doses showed inhibitory effect, while p50 / Live p50 dimer almost no effect. Tip, NF-kB in different immune organs in the composition and response to ionizing radiation there are differences.