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目的研究四氧化二氮(N2O4)对小鼠骨髓细胞姐妹染色单体互换(SCE)频率变化的影响。方法ICR小鼠,体重20~25 g,随机分为对照组和模型组,每组5只。染毒模型制作方法:将动物置于军事医学科学院提供的120 L染毒柜中,使用100μl微量注射器定量抽取液态N2O4,注入120 L染毒柜中。染毒柜内备微型电扇,以保证推进剂充分蒸发及均匀分布,维持染毒柜内N2O4浓度为70 g/m3,染毒时间15 min。SCE标本制备:小鼠饲养3个月后,将小鼠用乙醚麻醉,埋入5-溴脱氧尿核苷药片,24 h处死小鼠,于活杀之前腹腔按3μg/g体重注射秋水仙素液,制备骨髓的染色体标本。采用荧光+吉姆萨染剂分染法处理标本。SCE记数方法:先在中倍镜(20×)下选M2期细胞,再用油镜观察互换次数,凡在中间互换的记为2次;在末端互换记为1次。每只小鼠记数30个M2期细胞,结果以互换次数/细胞表示。与对照组小鼠比较SCE频率。结果N2O4染毒组的SCE频率(2.58)明显高于对照组(1.80)。结论结果提示N2O4中毒对DNA有一定的损伤作用,并影响遗传物质的稳定。
Objective To investigate the effect of nitrous oxide (N2O4) on the frequency of sister chromatid exchange (SCE) in mouse bone marrow cells. Methods ICR mice weighing 20-25 g were randomly divided into control group and model group with 5 rats in each group. Method of making the poisoning model: The animals were placed in a 120-L drug cabinet provided by the Academy of Military Medical Sciences, and liquid N2O4 was quantitatively extracted using a 100 μl microinjector and injected into a 120-L-toothed cabinet. Micro-fans were installed in the toxin cabinet to ensure that the propellant was fully evaporated and uniformly distributed. The concentration of N2O4 in the toxin cabinet was maintained at 70 g / m3 and the exposure time was 15 min. SCE Specimen Preparation: Three months after the mice were housed, the mice were anesthetized with ether and embedded in 5-Bromodeoxyuridine tablets. Mice were sacrificed 24 hours after injection, and colchicine Liquid, preparation of bone marrow chromosome specimens. The samples were treated by fluorescence + Giemsa staining. SCE counting method: first in the second lens (20 ×) under the M2 cells were selected, and then observed the number of interchangeable oil mirror, where in the exchange marked as 2 times; Each mouse counts up to 30 M2 cells, the result of which is expressed in terms of number of exchanges / cell. SCE frequency was compared with control mice. Results The frequency of SCE in N2O4 -treated group (2.58) was significantly higher than that in control group (1.80). Conclusion The results suggest that N2O4 poisoning can damage DNA to some extent and affect the stability of genetic material.