长期接触化学致癌物的实验室工作人员的姊妹染色单体互换频率

本文观察了长期接触化学致癌物的实验室工作人员的姊妹染色单体互换(SCE)频率的变化;发现第一、第二次测定的结果极其接近,且其SCE值的明显高于正常的非接触者。结果还表明,接触者与非接触者外周淋巴细胞对交联剂/致突变剂丝裂霉素C有相同的敏感性,证实接触者的淋巴细胞染色体的稳定性没有改变。文中讨论了接触者SCE 值改变的可能机理,为长期接触致癌物的实验室工作人员改善工作环境,减轻致癌物接触水平提供了实验根据。

THE OBSERVATION OF SISTER CHROMATID EXCHANGE FREQUENCIES IN THE WORKERS OF LONG TERM EXPOSURE TO CHEMICAL CARCINOGENS IN CANCER RESEARCH LABORATORY

The chemical compounds, N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), af-latoxin B1 (AFB1), benzopyrene (BP), dinitrosopiperazine (DNP) and 2-acetylami-nofluorene (2-AAF), are all powerful carcinogens and SCE inducers. This paper reports the SCE changes of the workers of long term exposure to those chemicals in cancer research laboratory in two years. The results showed that the SCE value detected in the exposer in first year approximated to that of the second year, and both were significantly higher than that of normal controls. The fact that the peripheral lymphocytes from exposer and normal controls are of the same sensitivity to mitomycin C verified that the chromosomes of lymphocytes from exposer have a normal stability. This suggested that although the variations of chromosomal stability in the exposer with normal DNA repair system do not occur in a given period of time, the long term exposure to carcinogenic environments can result in the damage of chromosomal DNA and the increase of SCE value.