Effects Of Cypermethrin On Antioxidant Enzymes And The Toxicity Study In Grass Carp (Ctenopharyngodon Idellus C.&V.)

The result of the acute toxicity tests of Cypermethrin, triazophos, phoxim to Grass Carp showed that the semi-lethal concertration (LC50) of Cypermethrin on 24, 48, 72, 96 hour of Grass Carp fingerling were 32. 82μg/L, 9.92μg/L , 8. 12μg/L , 6.51μg/;the semi-lethal concentration (LC50)of triazophos on 24, 48, 72, 96 hour of Grass Carp fingerling were were 1.93mg/L, 1.73mg/L, 1.60mg/L, 1. 499mg/L; the semi-lethal concentration (LC50)of phoxim on 24, 48, 72, 96 hour of Grass Carp fingerling were 15.34mg/L, 8.88 mg/L, 6.123mg/L, 5.74mg/L. The safe concentration to Cypermethrin, triazophos, phoxim are 0. 651μg/L, 0.1499mg/L, 0. 574mg/L. The Cypermethrin has obvious toxicities to Grass Carp, The order of acute toxicity to grass carp was Cypermethrin > triazophos> phoxim.According to the addictive index method of marking, the joint toxicities of Cypermethrin with triazophos were antagonistic on 24h,48h, 72h,96h; the joint toxicity of Cypermethrin with Phoxim was synergism on 24h and the joint toxicities of Cypermethrin with Phoxim were antagonistic on the 48h, 72h, 96h. The antagonistic action was stronger with the exposure time increasing.The gill and liver tissues of grass carp finglings were treated respectively at Cypermethrin levels (lμg/L, 3μg/L, 5μg/L)for 6h,12h, 24h and 72h;The results show that the SOD activities of gill tissues are higher than that of controlled groups before 6 h, but they are restrained during 12 h to 48 h, and finally recovered to the controlled groups standard in the 72hr. The SOD activities of live tissues were higher significantly than that in the control groups during 6h to 48h and come back to the control group level at the 72h. The Na*, K+桝TPase activity of live tissues but not significantly at the low concentration. It show a clear dose-dependenteffect. Cypermethrin show different pattern to Na+, K+-ATPase activity of gill, There was no clear dose-dependent effect, decreases was followed by increases.Applying scanning electric microscopic technique we oberseved gill tissue' s cytopathology of Cypermethrin to grass carp. The results showed that branchial leaflets was damaged and epithelia of gill was missing.Effect of cypemerthin on growth of primary hepatic and nephridical cells in grass carp were assessed by MTT colorimetry, The results showed that growth of cells were increased significant in lower cypemerthin groups .The growth of cells were decreased in the higer of the concentration of cypemerthin or the longer of exposure.The LCw of cypemerthin of cells were higher than fish in vivo. In conclusion , the toxicity of cypemerthin on hepatic and nephridical cells was no main reason to high lethal of grass carp.