^(147)Pm内污染诱导红细胞系统突变的适应性反应

The adaptive response of the micronucleated normochromatic erythrocytes from bone marrow and peripheral blood formed by 147 Pm irradiation of mice.

为探讨低剂量钷－ １４７（１４７ Ｐｍ） 内污染对红细胞系统遗传突变的影响，应用骨髓和血液正常染红细胞微核检测，观察了低剂量１４７ Ｐｍ 内污染小鼠能否改变相继高剂量１４７ Ｐｍ 内污染引起的红细胞染色体的损伤效应。结果显示，１８５ｋ Ｂｑ／ｇ 体重的单纯高剂量１４７ Ｐｍ 内污染可引起骨髓和血液正常染红细胞微核细胞率明显增多，与正常对照组比较有非常显著的统计学差异（ Ｐ ＜ ００１） 。然而，预先应用０３７ ，３７ 和３７ Ｂｑ／ｇ 体重的１４７ Ｐｍ 内污染预处理动物，３ 天后相继给予１８５ｋ Ｂｑ／ｇ 体重的高剂量１４７ Ｐｍ 内污染机体，骨髓和血液正常染红细胞微核细胞率明显减少，与单纯高剂量１４７ Ｐｍ 内污染实验组相比有显著或非常显著的统计学差异（ Ｐ ＜ ００５ 或 Ｐ ＜ ００１） ；并且与正常对照组相比已无显著性差异（ Ｐ ＞ ００５） 。结果表明，低剂量１４７ Ｐｍ 内污染预处理动物，可较长时间诱导红细胞系统的遗传适应性反应，使红细胞系统对相继高剂量１４７ Ｐｍ 内污染引起的染色体损伤有了明显的抵抗力。

The effects of low doses of internally deposited 147 Pm on the erythrocytes mutation from the peripheral blood and the bone marrow of mice induced by subsequent high dose of internally deposited 147 Pm were studied .Kunming male mice were injected through tail vein with low doses of 147 Pm(NO 3) 3 of 0.37,3.7 and 37 Bq/g body weight.Three days later the mice were injected with a high dose of 147 Pm(NO 3) 3 of 18.5 kBq/g body weight.The animals were sacrificed at 24 h after the injection of the high dose of 147 Pm.The experimental results show that the frequency of micronucleated normochromatic erythrocytes (mn-NCE)from the peripheral blood and the bone marrow of the mice exposed to the pure high dose of 147 Pm increased significantly over the controls at 24h after irradiation (P<0.01 ).However,the frequency of the mn-NCE from the peripheral blood and the bone marrow of the mice pre-exposed to 0.37～37 Bq/g of in vivo 147 Pm decreased significantly (P<0.01),as compared with that of the pure high dose of the 147 Pm injection group,and it doesn't have statistical difference than that of the controls (P>0.05).The results suggest that low doses of in vivo 147 Pm β irradiation can induce a adaptive response of the erythrosblasts in longer times,the radioadaptive erythrocytes have a obvious resistance to the radiogenetic damages induced by sebsequent high dose of internally deposited 147 Pm.Incorporating our previous studies,this may be due to the increase of DNA repair fuction in the radioadaptive cells.The induction of the adaptive response has a dose ranges .In the dose ranges lower dose of in vivo 147 Pm irradiation can produce higher level of the adaptive response. The frequency of the mn-NCE from the peripheral blood and the bone marrow of the mice is a more sensitive radiobiological parameter.