氨氮胁迫对黄河鲤幼鱼肝胰脏、肾脏抗氧化性的影响

为了探讨养殖水体中氨的毒性,在前期毒性实验的基础上设置氨氮质量浓度分别为0.071 mg·L-1、0.143mg·L-1、0.284 mg·L-1和0.427 mg·L-1的四个实验组和一个对照组对黄河鲤鱼(Cyprinus carpio)幼鱼进行毒性实验,实验期间pH值在7.80～7.85。分别在实验的0 d、7 d、14 d、28 d、35 d取样,检测肝胰脏、肾脏组织中超氧化物歧化酶(Superoxide Dismutase,SOD)、谷胱甘肽过氧化物酶(GSH-Px)活性和丙二醛(Malondialdehyde,MDA)的含量。结果表明,随氨氮暴露浓度的增加,黄河鲤鱼肝胰脏中的SOD和GSH-Px酶活性呈现先升后降的趋势,而MDA含量则呈现上升的趋势。方差分析表明,氨氮暴露浓度对于肝胰脏SOD活性、MDA含量影响效果极显著(P<0.01),且存在剂量-效应关系;随氨氮暴露浓度的增加,肾脏中SOD活性、GSH-Px酶活性均呈现先升后降趋势且效果显著(P<0.05),而肾脏中MDA含量呈现上升趋势且效果极显著(P<0.01),另外肾脏MDA活性与氨氮浓度之间存在显著的剂量-效应关系;氨氮暴露时间对于肝胰脏SOD活性、肾脏SOD、GSH-Px活性的影响表现为低浓度时先促进后抑制,高浓度时抑制,方差分析差异不显著(P>0.05)。可见,在实验浓度范围内氨氮降低鲤幼鱼的抗氧化能力,SOD、MDA可作为有效的生物标志物对氨氮引起的毒性做出评价。

Effect of ammonia on atioxidant in the liver,pancreas,and kidney of Yellow River Cyprinus carpio

To study the toxic effects of ammonia on the aquatic specials,four ammonia levels(0.071 mg·L-1,0.143 mg·L-1,0.284 mg·L-1,and 0.427 mg·L-1) with one control group were set for Cyprinus carpio for research.The samples were tested at the 1st,7th,14th,28th and 35th day.SOD、GSH-Px activities and MDA content of the liver,pancreas,and kidney were determined.The results showed that with an increase of the ammonia concentration,the activities of SOD and GSH-Px in the pancreas first increased and then decreased,and the MDA content exhibited a rising trend.It showed very significantly that ammonia exposure affected the content of MDA and activity of SOD by variance analysis(P<0.01),and they had a dose-effect relationship.Significantly,ammonia exposure affected the activities of SOD and GSH-Px in the kindey by variance analysis(P<0.05),and it was very remarkable that ammonia exposure affected the content of MDA in the kidney(P<0.01),and they had a dose-effect relationship.With the extension of ammonia exposure time,the activities of SOD in the liver,pancreas,and kidney,and GSH-Px in the kidney were promoted then suppressed at a low concentration.However,these activities were suppressed at a high concentration.It had no significant difference by variance analysis(P>0.05).Ammonia could reduce the oxidation resistance of the liver, pancreas,and kidney in the test concentration range,and the content of MDA and activity of SOD could be used as an effective biomarker for toxicity assessment of ammonia to Yellow River Cyprinus carpio.