苯诱导小鼠卵母细胞及1细胞合子雌原核染色体非整倍体的研究

Study on frequencies of aneuploidy in mouse oocyte and female pronucleus of one cell zygote induced by benzene

目的 研究苯对卵母细胞和 1细胞合子雌原核染色体非整倍体率的影响。方法 成年雌性NIH小鼠 ,1次灌胃 (942、1881和 376 2mg/kg)与多次吸入 (70 6、192 2和 486 4mg/m3 )染毒 ,灌胃后雌雄鼠以 1∶1同笼过夜 ,收集卵母细胞和 1细胞合子作细胞遗传学分析 ,测定非整倍体率。结果 小鼠吸入染毒 3个剂量组的第 2次减数分裂中期 (MⅡ )卵母细胞非整倍体率分别为 7 0 6 %、7 5 0 %和9 76 % ,明显高于对照组 (1 30 % ) ,有剂量 效应关系 ,同时也观察到第 1次减数分裂中期 (MⅠ )卵母细胞减数分裂停滞 ,MⅠ卵母细胞频率分别为 1 16 %、3 6 1%和 5 75 % ,高于对照组 (0 0 0 % ) ,有剂量 效应关系 ,在灌胃组仅见高剂量组MⅡ卵母细胞非整倍体率增高 ,1细胞合子雌原核非整倍体率未见增高。结论 吸入或灌胃给小鼠高剂量苯 。

Objective To study the effect of benzene on aneupoidy of oocytes and female pronucleus of one cell zygotes. Method The NIH adult female mice were treated with varies doses of benzene (942, 1 881 and 3 762 mg/kg respectively)via single gavage and(706, 1 922 and 4 864 mg/m 3, respectively)multiple inhalation After gavage, the mice were pair matched (1∶1) with males overnight The ovulated oocytes and the one cell zygotes were collected for cytogenetic analysis and the frequencies of aneuploidy were detected. Results The frequencies of aneuploid in MⅡoocytes significantly increased in the three groups treated with inhalation (7 06%, 7 50% and 7 76%, respectively, control group 0.00%, P <0 05)of benzene, as compared with those in the control group (1.30%), with a dose dependent response Meiotic delay of MⅠ oocytes was observed, with the frequency of MⅠ oocytes of 1 16%, 3 61% and 5 75%, respectively, P <0 05, in a dose dependent response, too In gavage treatment group, increase in frequency of MⅡoocyte aneuploidy was only observed in the high dose group, and aneupliody frequency of female pronucleus in one cell zygotes was not induced. Conclusion Exposure to high dose benzene via gavage or inhalation was able to induce increase in aneuploidy frequency of MⅡoocytes in mice