低剂量T-2和DON毒素致小鼠DNA损伤联合作用研究

The united effects on mouse DNA damage induced by minidose T-2 and DON toxin

目的观察低剂量T-2和DON毒素对小鼠DNA的毒性作用,探讨其远期致病效应及联合损伤作用。方法实验动物选用Balb/c小鼠,采用腹腔注射方式,进行慢性毒性实验。通过SCGE、ELISA、组织病理、TUNEL等方法观察不同处理组单个细胞基因组DNA损伤、血尿中8-OH-dG水平、肝脏组织形态学改变及肝细胞凋亡等指标来观察低剂量T-2毒素和DON对小鼠机体DNA的损伤作用。结果各组细胞拖尾率均随实验时间延长而升高,与对照组相比,DON组和联合用药组细胞拖尾率增高明显,差异有统计学意义。各实验组间比较可见,联合组拖尾率最高,与T-2毒素组相比,有统计学意义;就DNA损伤的综合指标(尾动量)来看,染毒组较对照组明显增加,各组间差异均具有统计学意义,以联合染毒组为最高。DNA加合物检测结果表明,T-2毒素组和联合毒素组小鼠尿中8-OH-dG含量明显升高,与对照组相比,差异有统计学意义。T-2毒素和DON均可使肝细胞出现病理损害,但二者损害形式不同,T-2毒素造成的肝细胞损害以嗜酸性变性和坏死为主,而DON引起的损害主要表现为气球样变性;同时给与两种毒素时嗜酸性变和坏死更明显;随着实验周期延长,各实验组损害加重。TUNEL检测结果表明,T-2和DON都可诱导肝细胞凋亡,但本实验3个染毒组之间,在凋亡细胞的发生率上未见明显的差异。结论低剂量T-2毒素和DON可对小鼠机体DNA造成明确损伤,表现为DNA断裂、加合物形成、细胞坏死及凋亡,联合染毒较单独染毒损伤更为明显。

Objective To investigate the toxic effect of minidose T-2 toxin and DON on mice DNA,to explore the long-term and united pathogenic effect.Methods Experimental animals were Balb/c mouse,the chronic toxicity test was performed using intraperitoneal injection.Through different investigation methods,such as SCGE,ELISA,histopathology and TUNEL to observe the single cell genomic DNA damage,8-OH-dG level in serum and urine,the morphological changes and cell apoptosis of liver,etc,to study the DNA damage induced by minidose T-2 toxin and DON.Results With experiment process,the occurring rate of Comet cell increased,compare with control,that in DON group and united group increased markedly,and the difference was significant. Among groups,that in united group was maximal,and compare with T-2 group,the difference had statistic significance. For the tail extent moment,treated groups were obviously higher than control. Among groups,the difference had statistic significance,and the most was in the united group. ELISA assay showed,the content of 8-OH-dG in urine of T-2 and united groups increased markedly,compare with control,the difference was significant.Both T-2 and DON could damage hepatocyte,but the pattern of manifestation was different,the damage induced by T-2 toxin was character for eosinophilic degeneration and necrosis,and that induced by DON was ballooning degeneration. Two kinds of toxin was treated at one time or with time increase,the damages aggravated. TUNEL result indicated,T-2 and DON could induce hepatocyte apoptosis,but the rate of apoptosis among 3 experimental groups has no significant difference.Conclusions Minidose T-2 toxin and DON toxin could surely damage DNA of mouse,showed DNA broken,DNA affixture formation,and cell necrosis and apoptosis,and the damage induced by T-2 toxin united with DON was severer than that caused by T-2 toxin or DON alone.