三唑磷对斑节对虾肝胰腺和鳃的氧化胁迫效应

Effects of Triazophos on Antioxidant Defense System of Hepatopancreas and Gills in Penaeusmonodon

采用半静态毒性实验方法测定了三唑磷(Triazophos,OP)对斑节对虾(Penaeusmonodon)的96 h LC50值,同时研究了低(0.3μg·L-1)、中(0.5μg·L-1)、高(1μg·L-1)浓度OP胁迫1、3、7、14 d和清水恢复7 d后斑节对虾肝胰腺和鳃中超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GPx)、丙二醛(MDA)含量和总抗氧化能力(T-AOC)的变化趋势。结果表明:在胁迫期间SOD、GPx活性都受到了显著的诱导和抑制,呈一定的变化规律;MDA含量随胁迫时间延长显著升高。肝胰腺T-AOC在低浓度OP胁迫下呈升高-下降-升高的变化趋势,高浓度则显著下降;鳃T-AOC显著升高,而随胁迫时间延长,T-AOC显著降低。经清水恢复7 d后,各浓度组肝胰腺SOD活性仍然显著低于空白组,MDA含量和T-AOC显著高于空白组。低浓度组鳃SOD、T-AOC显著高于空白组,MDA含量和中、高浓度SOD能恢复到正常水平,T-AOC则显著低于空白组。肝胰腺和鳃GPx活性变化情况相同,均为低、中浓度显著升高,高浓度显著下降。上述结果显示,OP对斑节对虾的抗氧化系统有显著的影响,且具有组织特异性,肝胰腺对OP较为敏感。斑节对虾对一定浓度OP所带来的氧化损伤具有一定的自我修复能力,但在短期内无法完全修复。

A semi-static toxicity test was used to determine the 96 hour median lethal concentration （96 h LC50 value） of triazophos （OP） on Penaeus monodon. Changes in activities of antioxidant enzymes [Superoxide dismutase （SOD）, glutathione peroxidase （ GPx ）], malondialdehyde（ MDA ） content, and total antioxidant capacity（T-AOC ） in hepatopanereas and gills of Penaeusmonodon were also studied immediately and 7 days of recovering in clean seawater after exposure to triazophos at 0.3 （low）, 0.5 （middle） and 1 （high）μg. L-1 for 1, 3, 7 days and 14 days. Activities of SOD and GPx were induced up to 7 days and then inhibited. Contents of MDA increased as the exposure time increased. At low doses of triazophos, T-AOC in the hepatopancreas followed an up-down-up pattern, while significantly decreased at high doses of triazophos. The gills T-AOC increased significantly at the first day, hut decreased after that. Recovery in clean seawater for 7 days still significantly inhibited SOD activity, but increased MDA and T-AOC in hepatopancreas compared with the control group. After 7 days recovery of gills, the SOD and T-AOC were still significantly elevated at low doses of triazophos, whereas T-AOC significantly decreased, but the SOD activity at middle and high doses of triazophos and MDA showed no difference, as compared with the control group. The GPx in hepatopancreas and gills significantly increased at low and middle, but decreased at high doses of triazophos. These results indicate that triazophos has tissue-specific impacts on the antioxidant system of P.monodon with hepatopancreas more sensitive, and that P. monodon has limited self-repair capacity under the triazophos stress.