四溴双酚A对霍甫水丝蚓的毒性效应研究

Toxic Effects of Tetrabromobisphenol A on Limnodrilus hoffmeisteri

以颤蚓属的霍甫水丝蚓(Limnodrilus hoffmeisteri)为受试生物,研究了四溴双酚A(TBBPA)的急性毒性和对颤蚓体内抗氧化酶以及乙酰胆碱酯酶(AChE)的影响。结果表明:TBBPA对颤蚓48、72、96 h的半数致死浓度LC_(50)分别为11.295、3.864、2.204 mg/L。暴露1 d和7 d后,颤蚓体内的超氧化物岐化酶(SOD)活性和过氧化氢酶(CAT)活性均在0.05 mg/L时产生最大诱导(P<0.01),其中暴露7 d的颤蚓CAT酶活性总体低于暴露1 d的CAT酶活性。在0.025 mg/L TBBPA暴露时过氧化物酶(POD)活性被最大诱导(P<0.01),分别为对照组的1.28和1.38倍。在0.25 mg/L TBBPA暴露时乙酰胆碱酯酶(AChE)活性被最大诱导(P<0.01),分别为对照组的1.25和1.20倍。在1 mg/L TBBPA暴露的10 d内,SOD、CAT和AChE活性均出现先升高后下降的变化趋势,其活性分别在第3天和第5天达到最大值(P<0.01)。POD活性的变化则分为降低、升高、再降低3个阶段,其活性在第3天到达峰值(P<0.01)。综上,TBBPA对颤蚓表现为高毒,且SOD、CAT、POD和AChE活性变化可以反映出TBBPA对颤蚓的污染胁迫。

The present study was aimed to evaluate the acute toxicity of tetrabromobisphenol A（TBBPA） and its effects on the activities of antioxidant enzyme and acetylcholinesterase（AChE） in Limnodrilus hoffmeisteri. The results indicated that the 48 h, 72 h, 96 h of LC（50） of TBBPA on Tubifex were 11.295 mg/L, 3.864 mg/L, 2.204 mg/L. After the 1-day and 7-day exposure, the highest superoxide dismutase（SOD） and catalase（CAT） activities（P〈0.01） were observed under 0.05 mg/L concentration of TBBPA. The CAT activities after the 7-day exposure were lower than that after the 1-day exposure in general. The peroxidase（POD） activities（P〈0.01） reached the highest value under 0.025 mg/L concentration of TBBPA（1.28 and 1.38 fold of that of control）. The AChE activities（P〈0.01） reached the highest value under 0.25 mg/L concentration of TBBPA（1.25 and 1.20 fold of that of control）. In a single concentration TBBPA exposed within 10 d, the changes of SOD and CAT and AChE activities were all increased initially and then decreased, and the peak values of them were detected after the 3-day and 5-day exposure, respectively. The POD activity showed a tendency of inhibited firstly and then enhanced gradually, at last inhibited again, and reached the peak value after the 3-day exposure. Overall, TBBPA was categorized as ＂high-toxic＂.Changes in the activity of SOD, CAT, POD and AChE could reflect the toxic effects of TBBPA on Tubifex.