Effects of atrazine and cyanazine on chlorpyrifos toxicity in Chironomus tentans (Diptera: Chironomidae)
Effects of atrazine and cyanazine on chlorpyrifos toxicity in Chironomus tentans (Diptera: Chironomidae)
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DOI：
10.1002/etc.5620210319
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发表时间：
2002-03
影响因子：
4.1
通讯作者：
Ying Jin-Clark;M. Lydy;K. Zhu
中科院分区：
文献类型：
--
作者：
Ying Jin-Clark;M. Lydy;K. Zhu
研究了两种三嗪类除草剂(阿特拉津和氰草津)和一种有机磷杀虫剂(毒死蜱)分别与毒死蜱复配后对水生摇蚊4龄幼虫的毒力。在48h急性毒性生物测定中，毒死蜱0.25μg/L对不到10%的蚊虫有效果。较高浓度(高达1,000μg/L)的阿特拉津和氰草津对淡色库蚊均无明显的急性毒性作用。然而，当阿特拉津或氰草津(10、100、1,000μg/L)与毒死蜱(0.25μg/L)混用时，阿特拉津和氰草津对毒死蜱的毒性有显著的协同作用。在固定浓度(200μg/L)的除草剂作用下，50%有效浓度水平的阿特拉津和氰草津对毒死蜱的毒力分别提高1.8倍和2.2倍。虽然阿特拉津和氰草津在体外对乙酰胆碱酯酶(AChE)没有有效的抑制作用，但这两种除草剂与毒死蜱的协同作用与体内对AChE的抑制作用有关。我们观察到，在一定浓度的毒死蜱存在下，AChE的抑制程度与阿特拉津或氰草津的浓度呈正相关。这些除草剂可能通过影响细胞色素P450酶，对毒死蜱的毒性产生协同作用。
Toxicities of two triazine herbicides (atrazine and cyanazine) and an organophosphate insecticide (chlorpyrifos) were evaluated individually and with each herbicide in binary combination with chlorpyrifos using fourth‐instar larvae of the aquatic midge, Chironomus tentans. Chlorpyrifos at 0.25 μg/L resulted in an effect in less than 10% of midges in 48‐h acute toxicity bioassays. Neither atrazine nor cyanazine alone at relatively high concentrations (up to 1,000 μg/L) caused significant acute toxicity to C. tentans. However, atrazine and cyanazine caused significant synergistic effects on the toxicity of chlorpyrifos when midges were exposed to mixtures of atrazine or cyanazine (10, 100, 1,000 μg/L) with chlorpyrifos (0.25 μg/L). At fixed concentrations (200 μg/L) of the herbicides, toxicity of chlorpyrifos was enhanced by 1.8‐ and 2.2‐fold by atrazine and cyanazine, respectively, at the 50% effective concentration levels. Although atrazine and cyanazine are not effective inhibitors of acetylcholinesterase (AChE) in vitro, the synergism of the two triazine herbicides with chlorpyrifos was associated with increased in vivo inhibition of AChE in midges. We observed a positive correlation between the degree of inhibition of AChE and the concentration of atrazine or cyanazine in the presence of a fixed concentration of chlorpyrifos. It is possible that these herbicides may affect cytochrome P450 enzymes to confer synergistic effects on the toxicity of chlorpyrifos.