镉对中华圆田螺抗氧化酶活性和脂质过氧化的影响

为研究水环境中重金属镉(Cadmium,Cd)对中华圆田螺(Cipangopaludina cathayensis)肝胰腺组织的抗氧化酶活性和脂质过氧化的影响,实验设置4个Cd2+染毒组(1.5、3.0、6.0和12.0 mg/L)和1个空白对照组,每组分别处理24、48、72和96 h后,测定中华圆田螺肝胰腺组织中的超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GPx)、谷胱甘肽转移酶(GST)和过氧化氢酶(CAT)的活力及谷胱甘肽(GSH)和脂质过氧化反应终产物丙二醛(MDA)的含量。结果显示,在暴露24 h时,随着Cd2+浓度的升高,SOD、GPx、CAT、GST和GSH的变化规律相似,均先升高后下降;同一浓度Cd2+暴露后,随着暴露时间的延长,SOD、GPx、GST 和CAT的活力、GSH含量均呈先升后降的趋势。随着时间延长和浓度增加,中华圆田螺肝胰腺组织中的MDA含量呈持续升高趋势。研究表明,中华圆田螺肝胰腺组织中抗氧化酶对Cd2+的毒性反应较灵敏,抗氧化酶活性变化水平和MDA含量的变化均可作为检测中华圆田螺Cd2+污染的生物指标,同时,肝胰腺组织亦可作为检测Cd2+毒性的靶器官。

Effects of Cadmium on Antioxidant Enzymes Activities and Lipid Peroxidation in Mudsnail(Cipangopaludina cathayensis)

As a potential indicator organism of freshwater pollution,the Mudsnail(Cipangopaludina cathayensis)was used to study the effects of Cd2+ on antioxidant enzymes and lipid peroxidation. The animals were exposed to a series of Cd2+ concentration(0,1.5,3.0,6.0 and 12.0 mg/L)for 96 h. Parameters including superoxide dismutase(SOD),glutathione peroxidase(GPx),catalase(CAT),glutathione S-transferase(GST),glutathione(GSH)and malondialdehyde(MDA)in the hepatopancreas tissues of Cipangopaludina cathayensis were determined at 24,48,72 and 96 h,respectively. The results showed that with the increasing of Cd2+ concentration,SOD,GPx,CAT,GST and GSH activities showed a trend of "rise and decline" at 24 h,while all decreased at 96 h. With the exposed time prolonging,SOD,GPx,CAT,GST and GSH also showed "rise and decline" at the same Cd2+ concentration. Meanwhile,the contents of MDA in hepatopancreas tissues of Cipangopaludina cathayensis increased with the time prolonging and Cd2+ concentrations increasing. These results suggested that the parameters of the hepatopancreas tissues of Cipangopaludina cathayensis were sensitive to Cd2+ toxicity,and could be used as biomarkers to evaluate Cd2+ pollution in water environment. Hepatopancreas could be used as a target organ to detect Cd2+ toxicity.