氨氮和重金属Cu^(2+)对放逸短沟蜷的急性毒性及氧化胁迫效应

Acute Toxicity and Oxidative Stress Effects of Ammonia Nitrogen and Heavy Metal Cu^(2+)on Semisulcospira Libertine

为了解放逸短沟蜷在环境胁迫下的生存能力,开展了氨氮和铜离子(Cu^(2+))对放逸短沟蜷的急性毒性试验。分别在氨氮和Cu^(2+)胁迫状态下,测定在放逸短沟蜷肝脏中超氧化物歧化酶(SOD)、过氧化氢酶(CAT)活性和丙二醛(MDA)含量的变化。结果表明,在氨氮胁迫下,放逸短沟蜷的安全浓度为3.51 mg/L;在Cu^(2+)的胁迫下,放逸短沟蜷的安全浓度为0.0835 mg/L。分别在低浓度和高浓度氨氮的胁迫下,随着胁迫时间的增加,放逸短沟蜷肝脏中的CAT和SOD活性均呈现先降低后升高的波浪式变化,而丙二醛(MDA)含量逐渐增加,且低、高浓度处理组均低于对照组并有显著的差异(P<0.05);分别在低浓度和高浓度Cu^(2+)胁迫下,随着胁迫时间的增加,放逸短沟蜷肝脏中的CAT和SOD活性均呈现先降低后升高的趋势,其肝脏中MDA含量增加,低、高浓度处理组均与对照组有显著差异(P<0.05)。指出,肝脏中MDA含量的增加,抑制了SOD和CAT的活性,导致放逸短沟蜷逐渐失去运动能力。

In order to explore the viability of Semisulcospira libertine under environmental stress,the acute toxicity test of ammonia nitrogen and Cu^(2+)to Semisulcospira libertine was carried out.The activities of superoxide dismutase(SOD),catalase(CAT)and the content of malondialdehyde(MDA)in the liver were measured under am-monia nitrogen and Cu^(2+)stress.The results showed that under the stress of ammonia nitrogen,the safe concentra-tion of Semisulcospira libertine was 3.51 mg/L,and under the stress of Cu^(2+),the safety concentration of Semisul-cospira libertine was 0.0835 mg/L.Under the stress of low concentration and high concentration of ammonia ni-trogen,with the increase of stress time,the activities of CAT and SOD in the liver decreased at first and then in-creased,while the content of MDA increased gradually,and the low and high concentration groups were signifi-cantly lower than those in the control group(P<0.05).Under low and high concentration of Cu^(2+)stress,the activi-ties of CAT and SOD in liver decreased at first and then increased with the increase of stress time,and the con-tent of MDA in liver increased.There were significant differences between low and high concentration groups and control group.The increase of MDA content in the liver inhibited the activities of SOD and CAT,and gradually lost the motor ability.