González Marina, Soloneski Sonia, Reigosa Miguel A, Larramendy Marcelo L
Laboratorio de Citogenética, Cátedra de Citología, Facultad de Ciencias Naturales y Museo, Universidad Nacional de La Plata, Argentina.
Mutat Res. 2003 Jan 10;534(1-2):145-54.
Single cell gel electrophoresis (SCGE) was used to analyse dithiocarbamate zineb- and the zineb-containing technical formulation azzurro-induced DNA damage and repair in CHO cells. Cells were treated with zineb (50.0 microg/ml) or azzurro (100.0 microg/ml) for 80min, washed and reincubated in pesticide-free medium for 0-12h until SCGE. Viability of treated cells (0 h) did not differ from control remaining unchanged up to 6h of incubation. After 12h, viability decreased up to 70 and 54% in zineb- and azzurro-treated cultures, respectively. SCGE revealed at 0 h the absence of undamaged cells and an increase of slightly damaged and damaged cells in zineb-treated cultures or by an increase in damaged cells in azzurro-treated cultures. For both chemicals, a time-dependent repair of pesticide-induced DNA damage within a 0-12h post-treatment incubation period was observed. Overall, damaged cells decreased as a function of the repair time for both pesticides while the slightly damaged cells decreased as a function of the repair time of zineb-induced DNA damage. Concomitantly, a time-dependent increase of undamaged cells was observed within the 0.5-12h repair time for both pesticides. At 12h after treatment, no differences in the frequencies of undamaged, slightly damaged and damaged cells were found between both zineb- or azzurro-treated cultures and control values as well as between zineb- and azzurro-treated cells. Immediately after exposure, nuclear DNA from zineb and azzurro-treated cells were larger and wider than nuclear DNA from untreated cells. When damaged cells were allowed to repair, a time-dependent decrease of the amount of free DNA migrating fragments was observed committed only to damaged cells but not in slightly or undamaged cells. On the other hand, no time-dependent alteration on nuclear DNA width within the 0-12h repair period was observed.
采用单细胞凝胶电泳（SCGE）分析二硫代氨基甲酸盐代森锌以及含代森锌的工业制剂阿祖罗对中国仓鼠卵巢（CHO）细胞DNA的损伤及修复情况。将细胞用代森锌（50.0微克/毫升）或阿祖罗（100.0微克/毫升）处理80分钟，洗涤后在无农药培养基中再孵育0至12小时直至进行SCGE检测。处理后0小时的细胞活力与对照组无差异，在孵育6小时内保持不变。12小时后，代森锌和阿祖罗处理的培养物中细胞活力分别下降至70%和54%。SCGE检测显示，0小时时，代森锌处理的培养物中未出现未受损细胞，轻度受损和受损细胞增加；阿祖罗处理的培养物中受损细胞增加。对于两种化学物质，在处理后0至12小时的孵育期内均观察到农药诱导的DNA损伤呈时间依赖性修复。总体而言，两种农药处理后受损细胞数量均随修复时间减少，而轻度受损细胞数量随代森锌诱导的DNA损伤修复时间减少。同时，在0.5至12小时的修复时间内，两种农药处理后的未受损细胞数量均呈时间依赖性增加。处理后12小时，代森锌或阿祖罗处理的培养物与对照组之间以及代森锌和阿祖罗处理的细胞之间，未受损、轻度受损和受损细胞的频率均无差异。暴露后立即观察到，代森锌和阿祖罗处理的细胞的核DNA比未处理细胞的核DNA更大更宽。当受损细胞进行修复时，仅在受损细胞中观察到游离DNA迁移片段数量随时间减少，而轻度或未受损细胞中未观察到这种变化。另一方面，在0至12小时的修复期内未观察到核DNA宽度随时间的变化。
