中文摘要：

采用静水生物测试法进行急性暴露试验,研究了有机磷类农药———乐斯本（LSB）对体质量为（20.0±1.7）g的克氏原螯虾Procambarus clarkii肝胰脏抗氧化系统的影响。试验设定2、10、20、40、80μg/L 5个LSB质量浓度梯度,每个浓度设2个平行,另设空白对照组和助溶剂二甲基亚砜（DMSO）对照组,每组投放克氏原螯虾20只,试验在聚乙烯塑料箱（58 cm×35 cm×34 cm）中进行。结果表明：药物浓度升高对克氏原螯虾产生较大毒性,半致死浓度（LC50）随着暴露时间的延长呈显著下降趋势,符合双曲线衰减模型（R=0.9999,P〈0.0001）,安全浓度为（2.79±0.31）μg/L;低LSB浓度染毒条件下,克氏原螯虾肝胰脏过氧化氢酶（CAT）活性随时间变化较小,在20μg/L LSB感染96 h时CAT活性达到最大值,之后随药物浓度的升高而降低,CAT活性随时间和药物浓度的变化呈极显著性差异（P〈0.001）;肝胰脏超氧化物歧化酶（SOD）活性变化与CAT活性变化相似,在时间和LSB浓度的共同作用下,SOD活性表现出显著性差异（P=0.045〈0.05）;LSB浓度对肝胰脏谷胱甘肽（GSH）含量的影响不大,在20～80μg/L浓度组,24 h和48 h的GSH含量有所下降,96 h的GSH含量则维持在较高水平,GSH含量变化在时间上出现了极显著性差异（P〈0.001）。本研究表明,肝胰脏SOD和CAT活性及GSH含量变化可以反映克氏原螯虾受损伤的程度,并可用作克氏原螯虾安全性风险评价的参考依据。

英文摘要：

Effects of Lorsban（LSB）on antioxidant system in hepatopancreas of red swamp crayfish Procambarus clarkii with body weight（20.0±1.7）g were studied in an acute exposure experiment by the static test method.The crayfish were stocked into polyethylene plastic tanks of each 58 cm×35 cm×34 cm at a rate of 20 individuals per tank and exposed to the LSB concentrations of 2,10,20,40,and 80 μg/L,and blank and DMSO groups as control with triplication.Results showed that the LSB had great toxicity to the crayfish at increasing concentration with the safe concentration of（2.79±0.31）μg/L.The LC50 of LSB was found to be decreased significantly with time and fitted a hyperbolic decay model with high R（R=0.9999,P0.0001）.The activities of superoxide dismutase（SOD）,and catalase（CAT） and glutathione（GSH） content in the hepatopancreas as the antioxidant indices revealed that there was little change in CAT activity at low LSB concentrations,the maximum activity in 20 μg/L group with in 96 h.With time procedure and increase in the drug concentration,however,CAT activity was shown to be very significantly lower（P0.001）.SOD activity was shown a similar trend as the CAT,significant differences（P〈0.05） in terms of time and concentration.There was no significant effect of the drug on the GSH content in 10 μg/L group,GSH levels being declined in 24 h and 48 h,and GSH levels being significantly higher in 96 h（P0.001）.It is concluded that the damage effect of red swamp crayfish is reflected in hepatopancreatic CAT,and SOD activities and GSH content as toxicological indicators.