低剂量131I内照射诱导小鼠胸腺细胞DNA损伤的适应性反应

目的 研究低剂量¹³¹I内照射诱导小鼠胸腺细胞DNA损伤的适应性反应。方法 用琼脂糖凝胶电泳和灰度值测定的方法确定低剂量¹³¹I(D1)和对小鼠胸腺细胞DNA具有明显损伤作用的¹³¹I剂量(D2),然后比较D1+D2组与D2组小鼠胸腺细胞DNA损伤的差异,D1、D2间隔为12 h。结果 根据DNA琼脂糖凝胶电泳和灰度值测定结果,发现D2组随着¹³¹I剂量的增加梯形条带清晰度和灰度值依次增加,最大损伤剂量D2是10⁶ Bq/g;D1+D2组DNA琼脂糖凝胶电泳梯形条带清晰度和灰度值比D2组明显下降,其中(10²+10⁶)Bq/g剂量组与(10³+10⁶)Bq/g剂量组DNA琼脂糖凝胶电泳梯形条带清晰度与灰度值10⁶ Bq/g剂量组比较下降最明显。结论 低剂量¹³¹I内照射能够诱导小鼠胸腺细胞DNA损伤的适应性反应。

Adaptive Response of DNA Damage on Thymocytes Induced by Low Doses Radiation of 131I in Mice

Objective To study the adaptive response of DNA damage on thymocytes induced by low dose radiation of ¹³¹I in mice. Methods Doses of D1 and D2 were determinted by the methods of agarose gel electrophoresis and gray value measurement. D1 was the low dose of ¹³¹I, D2 was the high dose of ¹³¹I that could cause obvious DNA damage on thymocytes. Then the divergence of DNA damage on thymocytes was compared between D1 + D2 group and D2 group. The interval time between D1 and D2 was 12 h. Results According to the results of agarose gel electrophoresis and gray value measurement,the clarity and gray value of DNA ladder were increased with the increasing doses of ¹³¹I. D2 was 10⁶ Bq/g. The clarity and gray value of DNA ladder were significantly decreased in D1 + D2 group compared to D2 group. Furthermore, the groups of 10² Bq/g + 10⁶ Bq/g and 10³ Bq/g + 10⁶ Bq/g decreased most. Conclusion Low dose radiation of ¹³¹I could induce adaptive response of DNA damage on thymocytes in mice.