炭黑颗粒诱发人B淋巴母细胞系遗传损伤的体外试验

Study of genetic damage of human B lymphocyte cell line induced by 14 nm and 280 nm carbon black particles in vitro

目的评价2种粒径炭黑诱发的人B淋巴母细胞的遗传损伤效应。方法人B淋巴母细胞经终浓度为0（溶剂对照）、128、256、384、512μg／ml的14、280nm炭黑颗粒染毒24、48h后，用微核试验、hprt基因突变试验和彗星试验进行检测。微核试验指标为微核率（MNR）、微核细胞率（MCR）、核芽（Buds）、核质桥（NPBs）、核分裂指数（NDI）和凋亡细胞。彗星试验指标为尾部DNA百分比（％tail DNA）和olive尾矩（OTM）。hprt基因突变试验指标为基因突变率（Mf-hprt）。结果14nm炭黑染毒48h组，浓度为384、512μg／ml时，％tail DNA、OTM分别为8．23％±0．19％、11．23％±0．42％和3．72±0．08、4．90±0．18，明显高于对照组（5．10％±0．08％和2．22±0．03），差异有统计学意义（P〈0．01）；凋亡细胞数分别为4．67±0．33、5．33±0．33，明显高于对照组（0．00±0．00），差异有统计学意义（P〈0．05）。hprt基因突变试验结果呈阴性。结论14nm超细炭黑细颗粒染毒48h可诱发人B淋巴母细胞DNA损伤，但280nm的炭黑颗粒未检测出类似效应。

Objective To assess the genetic damage of human B lymphocyte cell line induced by 14 nm and 280 nm carbon black （CB） particles with micronucleus assay （CBMN）, comet assay and hprt gene mutation test in vitro. Methods The genetic damage of human B lymphocyte cells exposed to 14 nm and 280 nm CB particles at the doses of 0, 128, 256, 384 and 512 μg/ml for 24 h and 48 h was detected using above three genotoxic assays. Micronucleus （MN） assay, comet assay, hprt gene mutation test were used to detect the genetic damage of human B lymphocyte cells induced by CB. Micronucleus rate（MNR）, micronu- cleated cell rate（MCR）, nuclear buds （Buds）, nucleoplasmic bridges（NPBs）, nuclear division index （NDI） and numbers of apoptotic cells served as indexes of CBMN assay;the percentage of DNA in the tail（% tail DNA） and the olive tail moment （OTM） were used as DNA damage indicators of comet assay; the hprt gene muta- tion frequency （Mf-hprt） served as the index of hprt gene mutation test. Results The % tail DNA, OTM in 14 nm CB group at the doses of 384 and 512 μg/ml for 48 h were 8.23%±0.19%, 11.23%±0.42% and 3.72±0.08,4.90±0.18,respectively,which were signifieantly higher than those in control （5.10%±0.08% and 2.22±0.03） （P〈0.01）. The apoptotie cell rates in 14 nm CB group at the doses of 384 and 512 μg/ml for 48 h were 4.67±0.33 and 5.33±0.33, respectively,which were significantly higher than in control（0.00±0.00）（P〈0.05）. The results of Mf-hprt were negative. Conclusion The genetic damage of human B lymphocyte cells exposed to 14 nm CB particles for 48 h could be detected. But the similar effects didn＇t appear in 280 nm CB group.