萘对斑马鱼（Danio rerio）内脏团抗氧化防御系统的胁迫与生物响应

经急性毒性实验，得到萘对成体斑马鱼96　h的半数致死浓度（LC₅₀）为11.8 mg·L^-1.在此基础上，设置5个浓度梯度：0、 1/6 LC₅₀、 1/4 LC₅₀、 1/3 LC₅₀、 1/2 LC₅₀，研究了在不同的暴露时间下（0.5、 1、 2、 4、 、 14d），萘对斑马鱼抗氧化防御系统的影响.结果表明，还原型谷胱甘肽（glutathione, GSH）、谷胱甘肽过氧化物酶（glutathione peroxidase, GPx）和谷胱甘肽硫转移酶（glutathione S-transferase, GST）对萘非常敏感，在暴露0.5　d时就受到抑制或诱导.0.5　d后GPx活性整体上被诱导，只在第14　d时高浓度组（1/3 LC₅₀和1/2 LC₅₀浓度组）GPx活性被抑制；GST和GSH则总体上是低于对照的.超氧化物岐化酶（superoxide dismutase, SOD）活性在2d后呈现先诱导后抑制；过氧化氢酶（catalase, CAT）活性在1　d后整体上受抑制.萘对斑马鱼内脏团抗氧化防御系统能产生影响，其变化可作为生物标志物，来评价暴露于多环芳烃有机污染的鱼类的生物学效应.

Stress and Biological Response of Naphthalene on the Antioxidant Defense System in Visceral Mass of Zebrafish (Danio rerio)

With the acute toxicity test, we obtained the median lethal concentration (LC₅₀) of naphthalene to the zebrafish for 96 h, which was 11.8 mg·L^-1. Then we set up five treatments(0, 1/6 LC₅₀, 1/4 LC₅₀, 1/3 LC₅₀ and 1/2 LC₅₀) and exposed zebrafish to these treatments for 0.5, 1, 2, 4, 7 and 14d respectively to study the effects of naphthalene on the antioxidant defense system in visceral mass of zebrafish. The results showed that GSH, GPx and GST were very sensitive to naphthalene and were inhibited or induced at 0.5 d exposure. The activities of GPx were induced on the whole after 0.5 d, but were inhibited at higher concentration treatments(1/3 LC₅₀ and 1/2 LC₅₀ treatments) at 14d exposure; while the activities of GST and the contents of GSH were almost lower than that of the control. The activities of SOD were induced first and then inhibited after 2d; the activities of CAT were inhibited almost in the all treatments after 1d. The effects of naphthalene on the antioxidant defense system in visceral mass of zebrafish could be used as biomarkers to estimate the biological effect of fish exposed to polycyclic aromatic hydrocarbons.