辛硫磷对岩原鲤肝脏抗氧化防御系统的胁迫与生物响应

Stress and Biological Response of Phoxim on Antioxidant Defense System in Liver of Procypris rabaudi

利用不同浓度的辛硫磷进行10d暴露试验,测定了辛硫磷对岩原鲤(Procypris rabaudi)的急性毒性效应和亚慢性毒性条件下,鱼体内过氧化物酶(CAT)、超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)、总胆碱酯酶(TChE)的活性和一氧化氮酶(NOS)、丙二醛(MDA)含量的变化,以期初步分析辛硫磷对岩原鲤抗氧化系统的作用及其毒性作用的可能机理。结果表明,辛硫磷对岩原鲤的96hLC50为2.9mg/L。CAT、TChE、NOS对辛硫磷非常敏感,在暴露初期就受到抑制或诱导,CAT和NOS总体上高于对照组,而TChE活性则总体上低于对照组。SOD、MDA、GSH-Px三者活性变化特征则各不相同;其中,SOD活性在辛硫磷污染下变化无显著规律;MDA含量则持续上升;辛硫磷浓度为0.5mg/L时GSH-Px活性变化比较微弱,变化规律也不明显,浓度为1.0mg/L和1.5mg/L时GSH-Px活性随着暴露时间的延长而上升。辛硫磷对岩原鲤抗氧化防御系统能产生影响,其变化可作为生物标志物,用来评价暴露于有机磷农药的鱼类生物学效应。

Under acute toxicity and subchronic toxicity of phoxim, the content variation of peroxidase （CAT）,superoxide dismutase（SOD）,glutathione peroxidase （GSH-Px ）,acetylcholinesterase （TChE）, nitric oxide synthase （NOS）, malondialdehyde （MDA） in Procypris rabaudi body was determined with exposure test of 10 d in different concentrations of phoxim （0.5,1.0 and 1.5 mg/L）, aiming at analyzing phoxim damage to the antioxidant system of P. rabaudi and the possible mechanism of the toxic effect.The results showed that the 96 h LC50 of phoxim to P. rabaudi Tchang was 2.9 mg/L. CAT, TChE, NOS were very sensitive to phoxim and were inhibited or induced at initial exposure stage, while the activity of CAT and the content of NOS were generally higher than those of the control, with the activity of TChE generally lower than that of the control. The characters of SOD, MDA, GSH-Px varied to different extents. Specifically, SOD activity presented irregular variation, and MDA content increased constantly, whereas GSH-Px activity had slight change without obvious regularity when the concentration was 0.5 mg/L. GSH-Px activity increased with exposure time extending, under the concentration of 1.0 mg/L or 1.5 mg/L. The experiment demonstrated that phoxim could have certain effects on the antioxidant defense system of P. rabaudi, and change of the defense system could be referred as biomarkers to estimate biological effects of fishes exposed to organophosphorus pesticide.