二甲苯对锦鲤鱼肝脏抗氧化酶的影响

摘要

An exposure experiment was conducted to study the effect of different concentrations of xylene on the activity of the antioxidant enzymes: superoxide dismutase (SOD) and catalase (CAT) in liver tissue of Cyprinus carpio. The results showed that it has not significant effect on the activity of SOD in the liver of Cyprinus carpio exposed to xylene at different concentrations. Only in the individual concentration and individual time, the activity of SOD was significantly induced or inhibited. The activity of CAT in the liver of Cyprinus carpio exposed to xylene was mainly induced, but in the concentration of xylene for 1/16 96hLC50 conditions, the reaction of the activity of CAT was slowly. However, with the increased of the exposure time, after 15 days, the activity of CAT, declined with the lower of the exposure concentrations. During the whole exposure experiment, the activity of SOD and CAT changed with synchronization. In the exposure of 3 days and 15 days, the activity of SOD was induced in the concentration of 1/4 96h LC50, the activity of CAT was also induced under the same conditions. In the exposure of 12 days, the activity of SOD was inhibited in the concentration of 1/8 96hLC50, the activity of CAT was also inhibited under the same conditions. In this exposure experiment, the activity of CAT was more sensitive to xylene, it reflected the existence of oxidation in the environment, it could be considered as the early pollution of biological monitoring index in the water environment.%采用暴露试验方法,研究了不同浓度二甲苯对锦鲤鱼肝脏组织中超氧化物歧化酶和过氧化氢酶的影响。结果表明,不同浓度组二甲苯在暴露期间对锦鲤鱼肝脏SOD活性的影响较小,只有在个别浓度和个别时间段下发生了显著诱导或抑制作用;锦鲤鱼暴露于二甲苯时对CAT活性影响主要表现为诱导作用,但CAT对1/16 96hLC50浓度二甲苯反应较滞后;随着暴露时间的延长,试验15 d后,CAT活性随着暴露浓度的降低而整体呈下降趋势;试验中CAT活性的变化与SOD活性的变化具有一定的同步性：在3 d和15 d时,1/4 96hLC50浓度组的SOD活性受到诱导,CAT活性也受到诱导;在12 d时,1/8 96hLC50浓度组的SOD活性受到抑制,CAT活性也受到抑制。在本次暴露试验中,CAT活性对二甲苯较敏感,从分子水平上反映了污染物对鱼体肝细胞的损伤,也反映了环境中氧化作用的存在,因此,可以考虑其作为水环境中二甲苯早期污染的生物监测指标。