以α-苯基-N-叔丁基甲亚胺-N-氧化物(PBN)为自旋捕获剂。利用电子顺磁共振(electron paramagnetic resonsnce。EPR)自旋捕集技术研究了在2,4-二氯苯酚(2,4-DCP)胁迫下,2、4、8、24、72h后鲫鱼(Carassius auratus)幼体肝脏活性氧的产生及其动力学.结果表明。2,4-DCP能引起鲫鱼肝脏中·OH的产生(与对照组相比具有显著性差异,p〈0.01),且其强度随时间的增加而增强。8h时达到最大,随后开始降低,赢至72h降至对照组水平.超氧化物歧化酶(Superoxide dismutase,SOD)活性随时间变化的动力学与·OH产生动力学趋势一致,暗示·OH可能由O2^-生成.GSH/GSSG比值随时间的变化趋势表明,机体处于氧化应激态.鲫鱼肝脏丙二醛(MDA)吉量明显增加,且与自由基产生的动力学相比滞后16h,表明脂质过氧化可能由·OH诱导产生.本研究表明,·OH对2,4-DCP的响应比抗氧化防御系统和脂质过氧化更直接、更快速,有可能成为指示水生生态系统中2,4-DCP污染的早期预警指标.
α-pbenyl-N-tert-butylnitrone (PBN) was used as spin trap reagent, followed by electron paramagnetic resonance (EPR) analysis, ROS generation in the liver of larval fish (Carassius auratus) was studied after 2,4-dichlorophenol (2,4-DCP) exposure for 2,4,8,24 and 72h. Results showed that there was a significant increase in ·OH generation in the liver of the fish after 2,4- DCP treatment (p 〈 0.01 ). Intensity of .OH increased with time, and it reached the maximum at 8h, then decreased to the control level at 72h. The relative similarity in the kinetics (from 2 to 72h) of supemxide dismutase (SOD) activity induction and .OH generation implied that the generation of .OH possibly depended on the superoxide anion (O2^- ). The ratio of GSH/GSSG changed over time suggested fish encountered the oxidative stress. MDA content was increased significantly in the 2,4- DCP treated groups compared with that of the control (p 〈 0.05 ). The kinetics of MDA level was found with a 16 h lag phase than that of .OH, which implied lipid peroxidation was possibly triggered by .OH. These results suggested response of .OH was much earlier and more direct than that of antioxidant defense, and therefore, it might have the great potential to be used as the early warning indicator to 2,4-DCP pollution.