The Effect Of Heavy Metal Fe³⁺ And Cd²⁺ On The Activity Of Loach Brain

In the water, heavy metal pollution is persistent, high perniciousness and intractability.How quickly and accurately to monitor and carry on the scientific evaluation has become ahot topic concerned with environmental science. A large number of studies show that thechanges of certain physiological indexes in aquatic organisms can reflect the degree ofheavy metal in polluted water. The problem of ecological toxicology was summarized inthis paper. At the same time, research progress of acetylcholinesterase as a biomarker thatis a key enzyme of biological neural conduction in monitoring heavy metal pollution wasreviewed.At present, although the researches of biological toxicity effect from the primaryheavy metal are more, but biological toxicity of heavy metals is still lack of research andunderstanding. Neurotoxicity of Fe3+as a heavy metal commonly has long been ignored.Especially, studies of Fe3+neurotoxicity have not been reported. In this study, the loach(Misgurnus anguillicaudatus) was chosen as experimental material. Firstly, the activity ofAChE has been compared among brain, intestine, liver and pancreas in loach. Then, theeffect of Fe3+on acetylcholinesterase (AChE) in loach brain was studied in vivo by usingthe kit for detecting technology. Results showed that the activity of AChE were1.42、0.35、0.06、0.15U·mgprot-1among brain, intestine, liver and pancreas, respectively. Andcompared with control, AchE activities in the brain were significantly decreased (p<0.05)after14day in60mg·L-1of Fe3+. The results of this study show that, although it isgenerally agreed that the toxicity of Fe3+is low, even very safe, but high concentrations ofFe3+also has great neurotoxicity.Using the same method, the effect of Cd2+on acetylcholinesterase (AChE) in loachbrain was studied from the comparison purpose. Activity of AchE in the brain wassignificantly decreased in0.3mg·L-1of Cd2+.By the first day, the fourth day, and seventhday compared, the longer the time, the lower the activity of AChE from the brain. Theresults implied that Fe3+and Cd2+might have neural toxicity on loach. Compared with the former, the latter has relatively greater toxicity. The loach live in the bottom of the waterand the mud, so that detecting the changes of AChE activity in brain tissue and theinfluence of loach can provide biological basis for the pollution status from heavy metalsin natural water.