Paraquat에 의한 흰쥐 Acetylcholinesterase 활성억제에 관한 연구 = Effects of Paraquat on the Activity of Acetylcholinesterase in Rat

다국어 초록 (Multilingual Abstract)

Paraquat (1,1'-dimethyl-4,4'bipyrydinium dichloride), a widely used herbicide, is extremely toxic to all green plants and many eukaryotic organisms. In human, paraquat intoxication lead to multiple organ failure. It damages preferentially lung, kidney, and liver and finally result in death. Acetylcholinesterase is present in the nerverous tissue and widely distributed in excitable membrane of nerve and muscle. The enzyme reversibly catalyzes the hydrolysis of acetylcholine to acetate and choline, which is a process necessary for cholinergic neurotransmission.
In this investigation, the effect of paraquat on the activity of acetycholinesterase in liver, lung kidney and brain of adult rat were investigated. The activities of acetylcholinesterase were reduced after exposure to paraquat especially in lung but the enzyme activity was uneffected in brain. The inhibition of acetylcholinesterase by paraquat appeared to be of a competitive nature, as determined by Lineweaver-Burk analysis. Paraquat radicals, produced by xanthine and xanthine oxidase system, has a more severe inhibitory effect on acetylcholinesterase activity than paraquat.
These results suggest that the decreased acetylcholinesterase levels in various organs of paraquat treated rat was probably due to the combined effects of destruction of the enzyme by paraquat induced free radicals and a inhibition of enzyme activity by paraquat radical.