低剂量T-2毒素与脱氧雪腐镰刀菌烯醇单独及联合染毒对小鼠末梢血有核细胞DNA损伤的观察

Investigation on DNA damage of mouse mononuclear cells in peripheral blood induced by low-dose T-2 toxin and deoxynivalenol alone or in combination

目的观察低剂量T-2毒素和脱氧雪腐镰刀菌烯醇（DON）对小鼠末梢血有核细胞DNA损伤的特点及其程度，探索亚临床剂量下的毒性作用。方法3周龄雌性Balb／c小鼠80只，体质量（14．0±1．5）g。将小鼠按体质量随机分为对照组、T-2毒素组、DON组、T-2＋DON联合组，每组20只。经腹腔注射感染毒素，染毒剂量：T-2毒素5ug·kg^-1·d^-1，DON 20ug·kg^-1·d^-1；对照组给予等量生理盐水。染毒至16周和21周，分别取小鼠尾血，用单细胞凝胶电泳法（SCGE）观察小鼠末梢血有核细胞拖尾率、尾DNA含量、尾长、尾动量变化。结果①T-2毒素组，尾DNA含量、尾长、尾动量[16周：（27．71±15．85）％、（13．67±5．56）um、4．26±3．83；21周：（28．38±15．57）％、（13．83±5．47）um、4．37±3．82]均增加，与对照组[16周：（11．87±4．61）％、（10．59±6．70）um、1．34±0．98；21周：（11．31±3．94）％、（10．83±7．05）um、1．29±1．01]比较，差异有统计学意义（P均〈0．05）；②DON组拖尾率、尾DNA含量、尾动量[16周：5．62％、（28．13±13．31）％、3．39±2．35；21周：7．71％、（29．17±15．12）％、5．70±4．17]均增加，其中仅拖尾率与对照组（16周：4.34％；21周：4．38％）比较，差异有统计学意义（P均〈0．05）；③T-2＋DON联合组拖尾率、尾DNA含量、尾长、尾动量[16周：6．21％、（30．14±15．48）％、（16．93±6．58）um、5．54±4．22；21周：8．17％、（30．85±15．76）％、（17．21±6．45）um、5．70±4．17]均增加，与对照组比较差异有统计学意义（P均〈0．05）；与T-2毒素或DON组比较，尾DNA含量和尾长均增加（P均〈0．05）。结论低剂量T-2毒素和DON均可对小鼠末梢血有核细胞DNA产生明确损伤；T-2和DON联合染毒较单独染毒的损伤作用更明显。

Objective To investigate the characteristics and extent of mononuclear cells DNA damage in peripheral blood of mice fed with low dose T-2 toxin and Deoxynivalenol（DON） alone or in combination and to explore the long-term toxicity of the toxin at sub-clinical dose. Methods Eighty female Balb/c mice weighing （14.0 ± 1.5）g 3 weeks after birth were divided randomly into control group, T-2 toxin group, DON group and T-2 toxin combined with DON group according to their body weight, 20 in each group. The mice were injected intraperitoneally T-2 toxin （5 ug·kg^-1· d^-1）, DON （20 ug·kg^-1· d^-1） , T-2 toxin （5 ug·kg^-1· d^-1 ） combined with：DON （20 ug·kg^-1· d^-1）respectively,control group were treated by isotonic NaC1. In 16 weeks and 21 weeks of exposure, the tail blood of the mice was collected. The comet rate, tail DNA content,tail length and tail extent moment of mouse mononuclear ceils in peripheral blood was observed using single cell gel electrophoresis（SCGE）. Results （1） In T-2 toxin group,tail DNA content,tail length and tail extent moment were （27.71 ± 15.85）%, （13.67 ± 5.56）um, 4.26 ± 3.83 at 16 weeks and （28.38 ± 15.57）%, （13.83 ± 5.47）um, 4.37 ± 3.82 at 21 weeks, all levels of the indexes increased. In the control group, the corresponding values were （ 11.87 ± 4.61 ）%, （10.59 ± 6.70） um, 1.34 ± 0.98 at 16 weeks and （11.31 ± 3.94）%, （10.83 ± 7.05）um, 1.29 ± 1.01 at 21 weeks, the differences in the two groups were significant（all P 〈 0.05）; （2）In DON group, the comet rate of cells, tail DNA content and tail extent moment of comet cells were 5.62%,（28.13 ± 13.31）%, 3.39 ± 2.35 at 16 weeks and 7.71%, （29.17 ± 15.12）%, 5.70 ± 4.17 at 21 weeks. In the control group, the tailing rate was 4.34% at 16 weeks and 4.38% at 21 weeks, the differences in the two groups were significant （all P 〈 0.05）; （3）In the group of T-2 toxin combined with DON,the comet rate, tail DNA content, tail length and tail extent moment was 6.21%, （30.14 ± 15.48）%, （16.93 ± 6.58）um, 5.54 ± 4.22 at 16 weeks and 8.17%, （30.85± 15.76）%, （17.21 ± 6.45）um, 5.70 ± 4.17 at 21 weeks. Moreover, the levels were significantly higher than that in the control group （all P 〈 0.05 ）. The tail DNA content and length of comet cell tail significantly increased in the combine group compared with T-2 group or DON group （P 〈 0.05 ）. Conclusions Low dose T-2 toxin or DON can definitely result in DNA damage of mononuclear cells in peripheral blood of mice. The damage induced by T-2 toxin combined with DON is severer than that caused by T-2 toxin or DON alone.