镉、苯并(a)芘胁迫对双齿围沙蚕SOD、CAT活性及MDA含量的影响

Influence of single and combined cadmium and benzo( a)-pyrene on SOD,CAT activities and MDA content in the Polychaete Perinereis aibuhitensis

为评估重金属、多环芳烃单一及复合污染对海洋多毛类抗氧化酶活性及膜脂过氧化水平的影响,分别以镉(Cd)、苯并(a)芘(B[a]P)作为重金属和多环芳烃的代表,研究了Cd、B[a]P及二者复合污染胁迫下双齿围沙蚕(Perinereis aibuhitensis)体内超氧化物歧化酶(SOD)、过氧化氢酶(CAT)活性和丙二醛(MDA)含量的响应特征。结果显示:Cd污染胁迫下,双齿围沙蚕体内SOD、CAT活性与Cd没有明显的"剂量-效应"关系,MDA含量则随其浓度升高而升高;B[a]P污染胁迫下,SOD、CAT活性及MDA含量均表现出明显的"剂量-效应"关系;Cd和B[a]P复合污染胁迫下,双齿围沙蚕体内SOD活性低浓度下被诱导,高浓度下被抑制,而CAT活性则随暴露浓度升高先降低然后恢复至对照水平,MDA含量仅在高浓度下被显著诱导(P>0.05)。本研究表明,Cd能够干扰B[a]P对沙蚕抗氧化系统的影响,二者复合污染胁迫表现为拮抗效应。

In order to elucidate the effects of heavy metal and polyaromatic hydrocarbons（ PAHs） on the antioxidant enzyme activity and lipid peroxidation in marine polychaetes,cadmium（ Cd） and benzo（ a） pyrene（ B[a]P） were selected as the representatives of heavy metal and PAHs respectively and the responses of antioxidant enzyme activities and lipid peroxidation in the polychate Perinereis aibuhitensis were studied when exposed to Cd,B[a]P and their combined pollution. Results showed that under Cd single pollution stress,there were no obvious dose- effect relationships between Cd concentration and the superoxide dismutase（ SOD） as well as catalase（ CAT） activities in P. aibuhitensis,while malondialdehyde（ MDA） content increased with increasing exposed concentrations. Under B[a]P single pollution stress,SOD,CAT activities and MDA content were all strongly correlated with waterborne B[a]P levels. Under combined pollution of Cd and B[a]P,SOD activity of P. aibuhitensis was induced in the lower exposed concentrations and inhibited in the higher exposed concentrations,CAT activity,however,was inhibited in the lowerexposed concentrations then returned to control level in the higher exposed concentrations. Meanwhile,MDA content was significantly induced only in higher exposed concentration. The current study suggests that Cd can interfere the influence of B[a]P on oxidation system in polychaetes and the combined exposure of the two pollutants made an antagonistic effect.