Cu^2＋急性毒性下银鲳幼鱼红细胞核异常和抗氧化酶活性的变化

Effcts of Cu^(2+) on acute toxicity,blood cell nuclear abnormal and antioxidant enzyme activity of Pampus argenteus

为探究Cu2+对银鲳幼鱼的致毒效应,采用静态毒性实验方法,开展了Cu2+对银鲳幼鱼的急性暴露实验,研究了不同浓度的Cu2+对银鲳幼鱼外周血细胞微核率、核异常率和肝脏抗氧化酶(SOD、CAT、GPX)活性变化的影响。结果表明:Cu2+对银鲳幼鱼48和96 h的LC50分别为0.860和0.770 mg/L,安全质量浓度为0.077 mg/L;Cu2+的浓度与银鲳幼鱼红细胞微核率及核异常率具有明显的剂量效应关系,在相同浓度Cu2+胁迫下,核异常率又普遍高于微核率;不同浓度Cu2+胁迫下银鲳幼鱼肝组织中的SOD、CAT、GPX活性均表现为低浓度被诱导而高浓度受抑制的规律,与Cu2+浓度呈抛物线型剂量效应关系。研究认为红细胞微核率、核异常率与SOD、CAT和GPX活性的变化均可以反映银鲳幼鱼受伤害的程度,并可用作银鲳安全性风险评价的参考依据,其中SOD还可以灵敏地指示低浓度的早期Cu2+污染。

An acute exposure experiment of copper on Pampus argenteus was carried out in a static biological test method. The abnormal rates of micronucleus and nucleus in peripheral blood cell,and the activities of antioxidant enzymes（ SOD,CAT,GPX） in liver were determined under different copper concentrations. The results showed that the 48 h and 96 h median lethal concentrations of copper were 0. 835 mg /L and 0. 543 mg /L respectively,and the safe concentration of the metal was 0. 054 mg /L. Copper was a drastic toxicant of Pampus argenteus,which indicated obvious dosage-effect relations with micronucleus rates and nuclear abnormal rates. Nuclear anomalies rates were generally higher than the micronucleus rates under the same concentration of copper; Activities of SOD,CAT and GPX changed greatly in the test groups which represented a tendency as increasing firstly and then decreasing from low concentration to high concentration. Antioxidant enzyme activity indicated parabolic dosage-effect relations. The changes of micronucleus rates,nuclear abnormal rates and the antioxidant enzyme activities（ SOD,CAT,GPX） indicated the damage degree of Pampus argenteus by Cu2 ＋. The SOD can also sensitively indicate early copper pollution of low concentration.