雌二醇、壬基酚、多氯联苯、镉和锌暴露对唐鱼体内超氧化物歧化酶活性的影响

目的 研究雌二醇(E2)、壬基酚(NP)、多氯联苯(PCBs)、镉(Cd2+)和锌(Zn2+)单独以及联合暴露对唐鱼体内SOD酶活力的影响.方法设计不同浓度的单一物质及混合物对唐鱼14 d暴露染毒,定量测定7、14d体内SOD酶活力的变化.结果 ①低浓度E2处理唐鱼7d可诱导SOD活性显著上升,时间延长、浓度升高时SOD活性无明显变化；②低浓度NP对SOD活性没有明显的影响,高浓度NP使SOD活性极显著上升；③中高浓度组PCBs处理7、14 d,低浓度组PCBs处理14 d时SOD活性被抑制,抑制程度随着时间的延长和浓度的升高有增强的趋势；④Cd2+、Zn2+各浓度组都对唐鱼体内的SOD活性产生了一定的抑制作用,并且抑制程度随着时间的延长而加深.结论 E2、NP、PCBs、Cd2+、Zn2+对唐鱼的SOD酶活力有明显影响,它们单独作用时的SOD活性与暴露浓度之间存在良好的剂量-效应关系.联合作用效应与暴露时间和(或)各物质浓度有关,大部分表现为毒性增强.

Effects of estradiol, nonylphenol, polychlorinated biphenyls, cadmium and zinc on the activity of superoxide dismutase in Tanichthys albonubes

Objective To study the effects of estradiol-17 beta （E2 ）, nonylphenol （NP）, polychlorinated biphenyls （PCBs）, Cd2＋ , Zn2＋ and their mixture on the SOD activity in Tanichthys albonubes. Methods T. albonubes were exposed to the substances mentioned above at different concentrations for 14 days. The activities of SOD at 7 days and 14 days were detected. Results The activity of SOD was significantly raised after the treatment at lower E2 levels for 7 days. It did not change obviously when the concentration of E2 was more increased or the exposure time was protracted. At the low concentration of NP, the activity of SOD almost had no changes, but it was raised observably at high concentration. The activity of SOD was decreased after exposure to middle and high PCB concentrations for 7 or 14 days, and so did it in low PCB concentrations for 14 days. Furthermore, the higher the concentration of PCB or the longer the exposure time, the more the SOD activity was decreased. All the Cd2＋ and Zn2. concentration groups designed in the study were found to restrain the SOD activity, and the SOD activity decreased more significantly with the extension of exposure time. Conclusions These substances obviously impact the SOD activity in T. albonubes. A good concentrationresponse relationship is found between SOD activity and E2 , NP, PCBs, Cd2 ＋ , Zn2 ＋ exposure concentrations. Compared with individual effects, the joint effects of these compounds are related to exposure time and （or） the mixture concentrations. Most of the combinations show an enhanced toxicity.