三氯异氰尿酸与盐酸环丙沙星对蛋白核小球藻的毒性效应

测试了典型渔药三氯异氰尿酸(Trichloroisocyanuric acid,TCCA)、盐酸环丙沙星(Ciprofloxacin hydrochloride,CPFX)对蛋白核小球藻(Chlorella pyrenoidosa)的急性毒性及其Ⅰ相、Ⅱ相代谢酶活性的影响.结果表明,TCCA和CPFX作用小球藻96h后EC50分别为0.31 mg·L-1和20.61mg·L-1.TCCA在低浓度下对小球藻Ⅰ、Ⅱ相代谢酶GSH、GST、CAT和EROD都存在诱导作用,当TCCA浓度大于0.13 mg·L-1时,对GSH、GST和EROD的诱导减弱.GSH、GST、EROD三种酶对CPFX作用的响应较弱,当CPFX大于70.20mg·L-1时,GST受到显著抑制,而EROD则明显升高,与对照组差异显著,GSH没有明显变化.CAT对CPFX作用的响应较敏感,表现为典型适应性诱导现象"钟形曲线",适合作为CPFX暴露的生物标记物.

Toxic effects of trichloroisocyanuric acid and ciprofloxacin hydrochloride on a freshwater alga,chlorella pyrenoidosa

Adverse effects of trichloroisocyanuric acid (TCCA) and ciprofloxacin hydrochloride (CPFX) to a freshwater alga, Chlorella pyrenoidosa were assessed through toxicity bioassays based on cell survival and enzymatic activities in Phase I and Phase II (GSH, GST and EROD). The results showed that 96h median effective concentrations (EC50) of TCCA and CPFX were 0.31 mg·L-1 and 20.61 mg·L-1, respectively. Enzymatic activities (GSH, GST and EROD) were found to be induced at low concentrations and decreased at higher concentrations of TCCA (>0.13 mg·L-1). No significant effects were observed for GSH, GST and EROD activities of Chlorella pyrenoidosa under low concentration exposure to CPFX, but when CPFX was above 70.20 mg·L-1, GST enzymatic activity decreased while EROD activity increased. CAT displayed a sensitive response to exposure to CPFX and exhibited a typical bell-shaped curve. Thus, CAT may be useful as a sensitive biomarker of exposure to CPFX.