环棱螺抗氧化系统对五氯酚钠毒性暴露的响应研究

Studies on Oxidative Stress of Sodium Pentachiorophenol in Bellamya sp.

在五氯酚钠(Sodium pentachlorophenol,PCP-Na)对环棱螺(Ballamya sp.)急性毒性实验的基础上研究了五氯酚钠的4个浓度(0.00、0.02、0.04、0.10 mg L-1)在连续96h的毒性胁迫下,对环棱螺肝脏中超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、还原型谷胱甘肽(GSH)和丙二醛(MDA)等生物标志物的影响。结果表明:各剂量组SOD和CAT在0～48h内酶活性总体先被抑制,48h之后均受诱导。0.02 mg L-1和0.04 mg L-1剂量组的GSH含量随胁迫时间的延长而逐渐增加,0.10 mg L-1剂量组肝脏中GSH含量在0～24h内表现为极显著升高(P<0.01),24～72h内GSH含量显著降低(P<0.05),72h之后GSH含量逐渐上升并最终恢复到对照组水平。各剂量组MDA含量表现为先升高后降低,最后恢复到对照组水平。结果提示,上述生物标志物在五氯酚钠对环棱螺进行毒性暴露过程中的变化较为敏感,可以作为指示五氯酚钠对环棱螺毒理效应的生物标志物。

A laboratory experiment was carried out to study the toxicity of Sodium pentachlorophenol(PCP-Na) on Bellamya sp.The variations of superoxide dismutase(SOD),catalase(CAT),malondialdehyde(MDA),glutathione(GSH) contents in liver exposed to different concentrations(0.00,0.02,0.04,0.10 mg·L-1) of Na-PCP for 96h were detected as biomarkers to evaluate toxicological effects of sodium pentachlorophenol.The results showed that the SOD and CAT activity of all groups in liver was inhibited at the beginning during the exposure period,but induced after 48 hours exposed.The GSH contents in liver of Bellamya sp.exposed to 0.02 mg·L-1 and 0.04 mg·L-1 of PCP-Na rose with time,while the GSH contents exposed to 0.10 mg·L-1 had an initial significantly increase(P<0.01),and followed by a significantly decrease(P<0.05) from 24 hours to 72 hours.After 72 hours exposed,the GSH contents recovered to the normal level.The MDA contents in liver of all groups increased at first but decreased later,recovering to the normal level at last.All these results suggested that biomarkers in this study were sensitive during Na-PCP espousing,which could be used as biomarkers of evaluating toxicological effects of Na-PCP on Bellamya sp.