溴氰菊酯胁迫下罗非鱼组织中过氧化氢酶和单胺氧化酶的变化

Activities of Catalase and Monoamine Oxidase in Different Tissues of Tilipia Under Stress of Deltamethrin

以罗非鱼Tilipia为试验鱼类,采用人工水族箱培养法,研究了其暴露于不同浓度溴氰菊酯后组织中过氧化氢酶CAT和单胺氧化酶MAO活性的动态变化。结果表明,罗非鱼肌肉和肝脏组织中的CAT正常值分别为(8.56±0.2)U.mg-1prot和(15.48±0.1)U.mg-1prot,MAO的正常值分别为(0.045±0.002)U.h-.1mg-1prot和(0.465±0.010)U.h-.1mg-1prot,均是肝脏组织高于肌肉组织。采用不同浓度的溴氰菊酯处理罗非鱼25d,除了1.0μg.L-1浓度组罗非鱼体内CAT和MAO与对照组相比无显著差异外,其余各浓度组的CAT和MAO均发生了明显的变化,两者的变化趋势正好相反。CAT的变化规律为先降低后升高,即溴氰菊酯对罗非鱼体内的CAT具有一定的抑制作用,可使鱼体内的CAT失活,且这种变化幅度肝脏比肌肉大。MAO的变化规律为先升高后降低再恢复,即溴氰菊酯对罗非鱼体内的MAO具有诱导和激活的作用,这种变化的幅度肝脏比肌肉小一些。研究表明,1.0μg.L-1以下的溴氰菊酯对罗非鱼没有生化毒性影响,罗非鱼组织中的CAT和MAO可作为生物标志物来评价农药对鱼类的生化毒性。

The activities of catalase （CAT） and monoamine oxidase （MAO） in the tissue of tilipia exposed to different concentrations of dehamethrin were studied. The results showed that the normal values of CAT and MAO were （8.56±0.2）U·mg^-1 prot. and （0.045±0.002） U·mg^-1 prot respectively in the muscle, and （15.48±0.1） U·mg^-1 prot and （0.465±0.010） U·mg^-1 prot prot respectively in the liver of tilipia.. The activities of the two enzymes in liver of tilipia were much higher than those in muscle. After treated 25 days, the test group of 1.0 μg· L^-1 dehamethrin had no effect on CAT and MAO in the tissue of tilapia, but the other test groups could cause obvious changes of CAT and MAO. There was opposite changing tendency between CAT and MAO. At the first 6 days, CAT decreased, showing that deltamethrin could inhibit the activity of CAT, afterward it began to increase. Changes of CAT in liver of tilipia were much more obvious than that in muscle. At the same time, MAO increased after treated 3 days, indicating the inducing effect of dehamethrin on MAO, but the changes of MAO in liver were less obvious than that in muscle. 1.0 μg· L^-1 dehamethrin had no biochemical toxicity to filipia. The activities of CAT and MAO in fishes could be used as biomarkers to asses the biochemical toxicity of the pesticide to fishes.