溴氰菊酯连续暴露对罗非鱼血清乙酰胆碱酯酶活性的影响

Effects of continuous exposure to deltamethrin on the acetylcholinesterase activity in blood serum of tilapia

以罗非鱼为受试生物，研究了不同水温（23℃～27℃）对罗非鱼血清中乙酰胆碱酯酶活性的影响，并在此基础上研究了不同浓度（1．0、2.0、3．0、5．0和10．0μg·L^-1）溴氰菊酯暴露下，罗非鱼血清中乙酰胆碱酯酶活性的动态变化。水温分别为23℃和27℃时，乙酰胆碱酯酶的活性分别为（2．75±0．21）和（2．73±0．26）U·ml^-1，活性波动范围分别为-12．0％～13．1％和-11.0％～14．2％。水温为（25±1）℃，染毒10d时，2．0μ·L^-1以上浓度的溴氰菊酯对罗非鱼血清中乙酰胆碱酯酶具有明显的抑制作用；染毒20d时，2．0μg·L^-1以上浓度的溴氰菊酯对其抑制率均超过40％；染毒25d时，5．0μg·L^-1的溴氰菊酯对其抑制率达到最大，为62．3％。实验结果表明：水温在23℃～27℃的波动不会对罗非鱼血清中乙酰胆碱酯酶的活性产生显著影响；水温为（25±1）℃时，高浓度溴氰菊酯（≥2．0μg·L^-1）会对罗非鱼血清中乙酰胆碱酯酶的活性产生抑制作用，而且抑制率随染毒时间的延长呈增加趋势。

This paper studied the acetylcholinesterase （ACHE） activity in blood serum of tilapia exposed to 1.0, 2. 0, 3.0, 5.0, and 10. 0 μg·L^-1 of deltamethrin at water temperature 23 ℃-27 ℃. The results revealed that the AChE activity was （2. 75 ±0. 21） U· ml^-1 at 23 ℃ and （2. 73 ± 0.26） U· ml^-1 at 27 ℃, with the variation range of -12.0% to 13. 1% and -11.0% to 14. 2%, respectively. After ten days exposure to 〉2. 0μg·L^-1 of deltamethrin at 25 ℃ ± 1 ℃, the AChE activity was inhibited, and the inhibition rate was surpassed 40% at the 20th day of exposure. The highest inhibition rate （62. 3% ） was observed on the 25th day of exposure to 5μg·L^-1of deltamethrin. The fluctuation of water temperature from 23 ℃ to 27 ℃ had no significant effects on the AChE activity, while high concentrations （ ≥2. 0 μg·L^-1） of deltamethrin could inhibit the AChE activity, and the inhibition rate was increased with exposure time.