花背蟾蜍性腺抗氧化酶对稀土尾矿库污染胁迫的响应

The Response of Antioxidant Enzyme in Bufo raddei Gonad to Rare Earth Tailings Pollution Stress

本研究以花背蟾蜍(Bufo Raddei)作为实验动物,以某稀土尾矿库周边受污染的水域湿地为研究样地,以相对无污染的小白河黄河湿地自然保护区为对照样地。通过检测两地花背蟾蜍精巢和卵巢的脏器系数、MDA和GSH含量、SOD、GSH-Px、GST、CAT和GR活性、T-AOC等相关指标。研究花背蟾蜍性腺抗氧化酶对该稀土尾矿库污染胁迫的响应效应。结果显示:与黄河湿地相比,稀土尾矿库湿地复合污染对花背蟾蜍精巢和卵巢脏器系数的影响差异不显著。稀土尾矿库花背蟾蜍精巢和卵巢中MDA含量、GPx、GST和CAT活性显著高于黄河湿地(P<0.05),而GSH含量表现出相反的趋势。精巢中T-AOC显著高于卵巢(P<0.01),但相同组织在两地间差异不显著。结果表明该稀土尾矿库复合污染对花背蟾蜍精巢和卵巢抗氧化能力有一定的毒害效应,且精巢和卵巢对污染胁迫的响应有明显的差异性。在应对稀土尾矿库湿地复合污染胁迫时,精巢更倾向于调用SOD-CAT系统的抗氧化机制,而在卵巢内GSH系统发挥作用更大。

This study uses Bufo raddei as the experimental animal. The polluted wetland at south side of a rare earth tailing was chosen as the study site, and the Yellow River＇ s Xiaobaihe wetland as the control site. The indicators including organ coefficients, MDA and GSH contents, and SOD, GSH-Px, GST, CAT and GR activities, and T-AOC were measured to study the response of antioxidant system in Bu^o raddei gonad to rare tailings pollution stress. The results showed that the testis and ovary organ coefficients of B. raddei in rare earth tailings site had no obvious difference compared with that in the Yellow River site. The MDA contents~ and GPx, GST and CAT activi- ties in testis and ovary of B. raddei in rare earth tailings site were significantly higher than that in the Yellow River site （P〈0.01）, while the GSH contents were lower than that in the Yellow River site. In both tailings and the Yellow River sites, T-AOC in the testis were significantly higher than that in the ovary （P〈0.05）, but there was no obvious difference between two sites in the same organ. The results indicated that the pollution of this rare earth tailing had certain toxic effects on antioxidant capacities in the testis and ovary of B. raddei The testis＇ and ovary＇ s antioxi- dant enzymes showed different responses to the rare tailings pollution stress. The SOD/CAT antioxidant system contributed more to the tolerance to the stress in the testis, while the GSH-related antioxidant enzymes play a more important role in the ovary of B. raddei.