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目的探讨类二噁英多氯联苯PCB126通过氧化应激损伤介导的胚胎发育毒性机制。方法用不同浓度的PCB126(0、16、32、64和128μg/L)对斑马鱼胚胎进行水触媒染毒,检测PCB126对不同发育阶段斑马鱼胚胎存活率、心包卵黄囊水肿率、心率及铜锌超氧化物歧化酶(CuZn-SOD)、过氧化氢酶(CAT)活性及丙二醛(MDA)含量的影响。结果从144 hpf后,随着PCB126浓度的增加,斑马鱼胚胎存活率明显下降(P<0.05),168 hpf时,128μg/L浓度组斑马鱼胚胎全部死亡;从96起,斑马鱼幼鱼心包卵黄囊水肿率显著增加(P<0.01),到144 hpf时,32μg/L浓度组水肿率达100%;在96和132 hpf时,128μg/L浓度组斑马鱼胚胎心率显著降低(P<0.01)。24 hpf时,各染毒组斑马鱼胚胎CuZn-SOD、CAT活性无明显变化,但64μg/L组MDA含量增加;72 hpf时,各染毒组CuZn-SOD活性降低,其中16和128μg/L组差异有统计学意义(P<0.01),64和128μg/L组CAT酶活性降低(P<0.05),32和128μg/L组MDA含量增加(P<0.05);96 hpf时,各染毒组斑马鱼CuZn-SOD及CAT活性均显著降低(P<0.01),32和128μg/L组MDA含量增加;132 hpf时,各染毒组斑马鱼胚胎CuZn-SOD和CAT活性均降低,MDA含量显著增加(P<0.01)。结论一定剂量的PCB126对斑马鱼胚胎发育具有致畸、致死作用,而氧化应激是其引起胚胎致畸、致死的重要机制之一。
Objective To investigate the embryonic developmental toxicity mechanism of dioxin PCB126 mediated by oxidative stress. Methods Different concentrations of PCB126 (0, 16, 32, 64 and 128 μg / L) were used to sensitize zebrafish embryos to water stress. The effects of PCB126 on zebrafish embryo viability, pericardial yolk sac edema, heart rate and copper (CuZn-SOD), catalase (CAT) activity and malondialdehyde (MDA) content were studied. Results After 144 hpf, the survival rate of zebrafish embryos decreased significantly with the increase of PCB12 concentration (P <0.05). At 168 hpf, all the zebrafish embryos died at 128 μg / L concentration. From 96 piglets, The edema rate of yolk sac increased significantly (P <0.01). At 144 hpf, the edema rate of 32 μg / L group was 100%. At 96 and 132 hpf, the heart rate of zebrafish embryos decreased significantly at 128 and 96 h ). At 24 hpf, there was no significant change in CuZn-SOD and CAT activity in zebrafish embryos, but the content of MDA in 64 μg / L group was increased. At 72 hpf, CuZn-SOD activity was decreased in all exposure groups, of which 16 and 128 μg / L (P <0.01). The CAT activity decreased in 64 and 128 μg / L groups (P <0.05), while MDA content increased in 32 and 128 μg / L groups (P <0.05). At 96 hpf, The activities of CuZn-SOD and CAT in the zebrafish were significantly decreased (P <0.01), and the contents of MDA in 32 and 128 μg / L groups increased. At 132 hpf, the activities of CuZn-SOD and CAT in zebrafish embryos decreased, Significantly increased (P <0.01). Conclusion A certain dose of PCB126 has teratogenic and lethal effects on zebrafish embryogenesis. Oxidative stress is one of the important mechanisms that cause embryo teratogenicity and lethality.