Nguyen Van Cong, Nguyen Thanh Phuong, Bayley Mark
College of Environment and Natural Resources, Cantho University, 3/2 Street, Cantho City, Vietnam.
Ecotoxicol Environ Saf. 2008 Oct;71(2):314-8. doi: 10.1016/j.ecoenv.2008.04.005. Epub 2008 Jun 2.
The snakehead Channa striata is an economically important air-breathing fish species in the Mekong delta of Vietnam. Rice paddies, which are disturbed by the frequent application of agro-chemicals, are among the preferred habitats for this species during the rainy season. Diazinon is one of most commonly used chemicals in rice paddies. In the present study, exposure of adult snakehead fish to a single diazinon application in cages within a rice field resulted in long-term brain cholinesterase inhibition, while the water concentration of this insecticide fell below the detection limit within 3 days. In addition, incubation of brain homogenates with 2-PAM caused reactivation of the cholinesterase diazinon complex to within 80% of the control level. These experiments also showed that chemical ageing of the diazinon cholinesterase binding occurred, which may explain the long-term effects of this pesticide.
条纹鳢是越南湄公河三角洲一种具有重要经济价值的呼吸空气的鱼类。稻田因频繁施用农用化学品而受到干扰，是该物种在雨季的首选栖息地之一。二嗪农是稻田中最常用的化学品之一。在本研究中，成年条纹鳢在稻田网箱中单次接触二嗪农后，脑胆碱酯酶受到长期抑制，而这种杀虫剂的水体浓度在3天内降至检测限以下。此外，脑匀浆与2-解磷定一起孵育可使二嗪农胆碱酯酶复合物的活性恢复至对照水平的80%以内。这些实验还表明，二嗪农与胆碱酯酶的结合发生了化学老化，这可能解释了这种农药的长期影响。
